An Observing Report from the English Lake District.

Posted on 17/08/2018 by Neil English

Plotina: a 130mm f/5 Newtonian that just goes on debunking myths promulgated by armchair astronomers, poodle pushers and fake theorists.

August 15 2018

Preamble: No doubt you’ve heard one or more of these statements before;

” My skies are never good enough to get steady views”

” The bleedin’ jetstream always gets the better of me.”

“The British Isles suck when it comes to doing visual astronomy.”

” Climate change is making our skies more cloudy, making small refractors more profitable to use.”

” It’s been cloudy for weeks and months on end.”

” My refractor cuts through the seeing like nothing else!”

What do they all have in common?

Lies, more damn lies, or gross distortions of the truth!

You see, I’ve been doing my homework, testing out a modest 130mm f/5 Newtonian reflector all over the British Isles, and finding that many places are plenty good enough for doing high-resolution planetary, lunar and double star observing. And from dark places, low-power, deep sky observing is also very much worthwhile.

Don’t believe me?

Do I sound like I care?

Stick this in your proverbial pipe and smoke it: if only you got off your big, fat, wicked, lazy butt and did some real testing you’d soon come to a knowledge of the truth!

Moi? I’ve observed with the same telescope from no less than five counties in Southern Ireland, the windswept Isle of Skye in Northwest Scotland, Aviemore in the heart of the Scottish Highlands, and rural Aberdeenshire in Northeast Scotland, Wigtown in Southwest Scotland, Seahouses in Northeast England and even in the heart of the large cities of Glasgow and Edinburgh. Most recently, I tested a site in southern Lakeland, Cumbria, the subject of the present observing report.

Thus far this year, I have logged 78 separate sessions under the stars (not all perfectly clear and not all long sessions), either at home here in my rural site just north of the Scottish Central Belt, or while on holiday, and no doubt there were still more nights when I was unable to observe or it cleared too late or some such to conduct any more observations. That’s 78 out of 226 nights, or just shy of 35 per cent! So, more frequently than one in every three nights proved profitable. But I suspect the figure is nearer 40 per cent.

How do these data resonate with the above statements?

They don’t, do they?

Get yer logbooks oot……lemme see yer logbooks.

Sheer dumb luck?

Don’t give me that either!

I don’t believe in sheer dumb luck. Nor do I spend my precious time haunting telescope forums, you know, drooling over this instrument or that.

Nope; I’m an observer!

So I just go observing lol. You know, actually looking through my telescope; it’s not so hard is it?

Anyone with a deep enough interest in such things would quickly draw the same conclusions, at least on the British Isles.

Do I believe these findings are unique to Britannia et Hibernia?

Hell no!

Why should they be?

Surely, most of these observations were conducted during warmer, more settled spells, like in Summer?

Nope, computer says no! Check my logbooks!

Good spells occur in all weathers, from freezing cold nights to sweltering hot ones!

Have these data any historical precedents?

Absolutely yes!

See my up-and-coming book, Chronicling the Golden Age of Astronomy, for a full disclosure.

If you take the time to examine the frequency of key historical figures who loved the night sky, you’d find fairly similar results in the literature.

How do I know?

I’ve studied those historical cases.

Phew! Quite a rant there!

But better a rebuke than faint praise eh?

Now, shall we get down to business?

Introduction:

Plotina; the author’s ultra-portable 130mm f/5 Newtonian sampling the skies from the southern Lake District, Cumbria, England.

A 5.1″ f/5 Newtonian was transported in its custom aluminium case to a site in Southern Lakeland, Cumbria (Latitude: 54.5 degrees North) to establish whether conditions were good enough to resolve a number of test double stars and to more generally assess the seeing and transparency at this location. The success of this modest ultra-portable instrument at various sites within the UK and Ireland has been truly remarkable, so much so that this author has totally abandoned more traditional instruments such as Maksutovs and refractors in favour of this small Newtonian to pursue all areas of grab ‘n’ go amateur astronomy. As explained in a number of previous blogs, the telescope sports a significantly greater aperture (130mm) than your run-of-the-mill grab ‘n’ go telescopes. Possessing a high quality optical flat resulting in a modest 27 per cent (linear) central obstruction, it is significantly smaller than all commercial catadioptrics and sports very high reflectivity coatings that produce bright, crisp images, very comparable to an equivalent sized refracting telescope. In addition, its relatively low mass and open-tubed optics ensures that it cools more rapidly than a similar-sized refractor or catadioptric.

During the trip, just one evening turned out clear, namely the night of Friday, August 10-11 2018.

Conditions:

Mostly clear with some patchy cloud. Temperatures were cool (12C), with a brisk south-westerly breeze, which continued to gust for several hours, abating almost entirely by local midnight. Transparency proved very good and although there was some light pollution owing to neighboring mobile homes, the sky was good and dark. Indeed, I judged the site a little darker than at my rural observing site in Scotland, with the northern Milky Way seen more prominently, snaking its way from northeast to southwest. The northern and eastern sky was especially dark, prominently revealing the majestic constellations of Cassiopeia, Andromeda, Pegasus, while high overhead lay Cygnus and Lyra. The site had a good view of the southern sky, with Aquila and Delphinus situated very close to the meridian. Two bright planets graced the southern sky low down, a dull yellow Saturn and further east, brilliant red Mars.

Method:

The telescope was precisely collimated using a good quality Chesire eyepiece and left to cool for about 20 minutes, with the open tube pointing straight into the prevailing (south-westerly) winds at the site. A working magnification of 260x was adopted to examine a number of test double stars. This was achieved by coupling a 7.5mm Parks Gold eyepiece and Meade 3x achromatic Barlow lens.

For widefield sweeping, a 25mm Celestron X-Cel LX was used, deliverng a power of 26x in a 2.3 degree true field. Higher power deep sky views were enjoyed with a 5.5mm Meade ultra-wide angle ocular which yields a power of 118x in a 0.7 degree true field. Mars and Saturn were observed at a power of 177x (using an 11mm eyepiece and 3x Barlow), which proved more than adequate, as both orbs were situated very low down in the southern sky around local midnight.

The test double stars were chosen for their easy accessibility as well as being progressively more difficult;

Epsilon 1 & 2 Lyrae

Epsiion Bootis

Delta Cygni

Mu Cygni

Pi Aquilae

Lambda Cygni (examined at 354x using a 5.5mm eyepiece coupled to a 3x achromatic Barlow).

Double Star Results:

The first five test systems produced text-book perfect splits at 260x, the components being very cleanly resolved, and the individual stars presenting as perfectly round Airy disks with a single but rather subdued diffraction ring. The sub-arcsecond pair, Lambda Cygni, revealed its near-equal magnitude components as ‘kissing’ at 354x. You can’t do that with a 4-inch refractor; see here for just one example.

Additionally, the wonderful triple star system, Iota Cassiopeia, was examined later in the vigil, when the constellation had risen higher in the northeastern sky. I was rewarded with a perfectly resolved rendering of all three components at 260x using the 130mm f/5 Newtonian.

Conclusions:

Despite enjoying just one clear night at this site during our short vacation, I achieved what I have come to view as fairly typical results for many locations in the British Isles. The telescope was able to deliver excellent high-resolution results on these test double stars. As stated earlier, I do not especially attribute these results to serendipity. Indeed, I have come to expect such results when conditions are reasonable at many sites within the UK and Ireland. Such results can easily be achieved by other observers using the same (read modest) equipment with just a little attention to detail; adequate acclimation and close attention to accurate collimation, which can be executed perfectly in under a minute. I would encourage others to test these claims so that these results become as widely known as possible.

Newtonian telescopes will continue to be my instruments of choice to observe such systems in the future, so as to help dispel a particualrly virulent myth that has arisen within the amateur community; a myth born out of ignorance and old fashioned laziness. Such a myth is plainly false and will allow many more observers to pursue such targets with unpretentious instruments that are very reasonably priced.

Observing the Planets:

Although certainly not a dedicated planetary observer, I have come to appreciate the very good views of Jupiter in recent apparitions using the 130mm f/5 Newtonian. During this vigil, my family and I enjoyed very nice, crisp images of Saturn with the telescope at 177x. Despite its low altitude in the southern sky, the planet revealed its glorious white rings with the Cassini Division being plainly seen. Some atmopsheric banding was also observed but, being much farther away, these features are much more subdued than on mighty Jupiter.

Mars was examined at the same power. This was actually the very first time the planet was observed telescopically during the present apparition. The view served up by the telescope was shockingly good and to be honest, not at all anticipated owing to its even lower altitude near the southern horizon. First off, I was amazed at how large the planet looked at 177x (a rather low power for a 5.1″ telescope on such a target generally). Though the image was roiling in the perturbed atmosphere near the local horizon, I was able to make out some dark markings on the planet as well as a rather subdued southern polar ice cap. I was aware that the planet had recently experienced a planet-wide dust storm that all but occluded many of the surface features but I was pleased to see that, while much dust was still present in the atmosphere, it was clearly settling out at the time the observations were made. Mars was a big hit with the family; its large size and great brightness to the naked eye being a lively topic of conversation with my wife and sons.

Into the Deep Sky:

Plotina is a step above the rest of the grab ‘n’ go herd with regard to deep sky observing. It’s highly efficient 5.1″ primary mirror collects enough light to put it in a different league to 90 and 100mm refractors.

How do I know?

I’ve done extensive tests with a 90mm Apo (shown below) and my notes show that double stars hard to see with a four inch refractor are easier to see and resolve in the 130mm reflector. It’s not rocket science!

Faster, cheaper, better: The author’s 130mm f/5 modified Newtonian( Plotina) enjoying crisp, bright terrestrial views and in a completely different league to a 90mm f/5.5 ED apochromat(left).

With the glorious return of true darkness to northern British skies, my first port of call was the endlessly glorious Double Cluster in Perseus. This is where the 25mm Celestron X-Cel LX eyepiece really shone through for me. I don’t know if you’ve ever held on to an eyepiece because of how well it frames a deep sky object, but this ocular delivered an absolutely beautiful, expansive view of the famous open clusters. It’s very comfortable 60 degree AFOV delivers a true field of 2.3 degrees at 26x, centring the clusters perfectly in the middle of the field and showing just enough of the rich stellar hinterland to render the experience particularly memorable. The perfect achromatism of the Newtonian delivers the pure colours of the white, yellow, blue and ruby coloured suns decorating these wonders of nature, each of which are located over 7,000 light years away. I stared at these clusters for a full 10 minutes before dragging my eyeball away!

Next, I pointed the telescope into the heart of Cygnus and drank up the sumptious views of the northern Milky Way, moving the instrument slowly from field to field in awe of the sheer number of stars this wonderful 5.1-inch pulled in. Sometimes deep sky observing is not about seeking out any particular object; for me, it often involves just sweeping the telescope through an interesting swathe of sky, sitting back and enjoying the visual sensations that bring joy to the eye-brain.

My telescopic sojourns eventually took me into Vulpecula, where I quickly chanced upon Brocchi’s Cluster (Collinder 399), otherwise known as the Coathanger, owing to its extraordinary configuation of half a dozen stars arranged just like its common name suggests and spanning over 1.5 degrees of sky, which was easily handled by the 25mm Celestron ocular.

Skies were good and dark enough to observe a number of planetary nebulae in Vulpecula, Lyra and Hercules and for these, I switched out the 25mm ocular for the 5.5mm Meade Ultrawide angle delivering 118x in a fine 0.7 degree true field. Easy to pick up in my 6 x 30mm finder as an 8th magnitude smudge, the 5.1-inch Newtonian delivered an awesome view of M27, the famous Dumbbell Nebula, its enormous size occupying a space fully a quarter the size of the full Moon. I find such structures haunting in the telescope and a kind of shiver went down my spine as I studied its enormous bi-lobed morphology alone in the dark (the wife and kids having now retired for the night). Moving west into Hercules nextdoor, I sought a spot about 4 degrees northeast of the fairly bright star, Beta Herculis. With the generous, wide field of the 5.5mm I didn’t have to switch out for a lower power eyepiece to find the lovely 9th magnitude planetary, NGC 6210. The telescope made light work of picking up its distinctive oval shape and its soft bluish hue. Finally I ventured east again into Lyra, where the telescope made light work of picking up the endlessly interesting M57, the famous Ring Nebula, easily located smack bang in the middle between Beta and Gamma Lyrae. At 188x, this planetary looks big and bright with its inner and brighter outer structures showing up well. It’s amazing that this luminous smoke ring in the August sky is estimated to be a full light year in diameter!

Having studied the bright and comparitively huge globular clusters, M13 and M92 at home in Scotland with my 12″ f/5 Dob, I was impressed at how well they presented themselves in the little 5.1-inch lightcup at 118x. I was in for a bit of shock though when I eventually tracked down M56 in Lyra, located roughly half way between Albireo and Gamma Lyrae. In the 5.5mm eyepiece, this globular was considerably smaller and fainter, looking more like a nebula than anything else. When I cranked up the power to 177x, the view was little improved; just a bright but unresolved core with a smattering of faint stars hovering like little fireflies around it. The view in my 8-inch Dob is far better but still rather lacklustre. I find my 12-inch Dob to do proper justice to this cluster and its gorgeous hinterland of Milky Way stars.

I ended my vigil in the wee small hours of Saturday morning, August 11, with a ceremonial visit to M31 and its satellite galaxies, now riding about one third of the way up the eastern sky. To be honest, galaxies never do much for me and I don’t really understand why folk in possession of larger instruments want to look at them in very small telescopes. Some say it’s heroic and admirable to do that kind of thing but I think it’s bordering on nuts. Why struggle to observe such faint fuzzies when you can more easily study them in larger telescopes? Anyway, the decent light grasp and expansive 2.3 degree field of my new Celestron LX ocular delivered a sterling view of this showpiece object of the autumn sky.

It was good to get away; our first visit to the beautiful Lake District. But all good things have to come to an end I guess.

The author did not emerge from pond scum and cannot for the life of him understand why anyone else would have such a low opinion of themselves. Such are the false fruits of evolutionary ‘science.’

De Fideli.

Living without Lasers

Posted on 14/08/2018 by Neil English

Collimation tools; from left right: a SkyWatcher Next Generation laser collimator, a collimation cap, a well made Cheshire eyepiece and a Baader lasercolli Mark III.

It is undoubtedly true that by far the most prevalent reason why so many amateurs have dissed Newtonian reflectors in the past boils down to poorly collimated ‘scopes which lead to less than inspiring images. The amateur who pays close attention to accurate collimation will however discover the solid virtues of these marvellous telescopes and will soon forget the bad experiences of the past.

I’ve noticed a trend over the last few decades, where more and more amateurs have become lazy and impatient. They want instant gratification. This is one of the main reasons why many have turned to hassle-free instruments such as small refractors and Maksutov Cassegrains. It’s an entirely understandable trend, but in other ways it is lamentable. One of the downsides of this trend is that amateurs have become less concerned with learning practical optics, deferring instead to higher tech ways of obtaining optimal results in the field. One such technology is the laser collimator; a very useful device that has made accurate collimation far less of a chore than it was just a few decades ago. But while many have defaulted to using such tools as labour-saving devices, they have, at best, become less familiar, or at worst, all but forgotten the traditional tools used in the alignment of telescope optics; tools such as the collimation cap and the Cheshire eyepiece, and in so doing have less and less understanding of how their telescopes actually work.

The desire for super-accurate collimation has undoutedly been fuelled by the advent of faster optical systems; often supporting sub-f/5 primaries. Once, the traditional Newtonian was almost invariably made with higher f ratios:- F/7 to f/10 and beyond, and requiring very little in the way of maintenance. This is abundantly evidenced by the scant attention astronomy authors of the past gave to such pursuits. In contrast, modern Newtonians are usually f/6 or faster, necessitating much greater attention to accurate optical collimation if excellent results are to be consistently attained during field use.

In my chosen passtime of double star observing, I have acknowledged the need for accurate collimation. Such work often requires very high magnifications; up to and in excess of 50x per inch of aperture, to prize apart close double stars, some of which are below 1 arc second in angular separation. At such high powers, sub-standard collimation results in distorted images of stellar Airy disks, and that’s something that I’m not willing to put up with. In this capacity, I have tested a number of collimaton techniques using a few different laser collimating devices but have also spent quite a lot of time comparing such methods to more traditional techniques involviing the tried and trusted collimation cap and Cheshire eyepiece.

To begin with, it is important to stress that the methods covered in this blog can be achieved easily with a little practice, and I will gladly defer to recognised authorities in the art of Newtonian collimation, such as the late Nils Olif Carlin and Gary Seronik, who have done much to dispel the potentially stressful aspects of telescope collimation. Nothing I will reveal here goes beyond or challenges anything they have already said. My goal is to reassure amateurs that one can happily live without lasers, especially if your Netwonians are of the f/5 or f/6 variety.

Many of the entry-level laser collimators often manifest some issues; partcularly if they are not collimated prior to use. Thankfully, the inexpensive SkyWatcher Next Generation that I have used for a few years did come reasonably well collimated, but others have not been so fortunate. One easy way to see if your laser collimator needs collimating is to place it in the focuser of the telescope and rotate it, examining the behaviour of the beam on the primary. If the beam does not stay in place, but traces out a large annulus, you will have issues and will need to properly collimate the laser. This is not particularly difficult to do and many resources are available on line to help you grapple with this problem. See here and here, for examples.

Of course, you can pay extra for better made laser collimators that are precisely collimated at the factory. Units that have received very good feedback from customers include systems manufactured by Hotech, AstroSystems and Howie Glatter. Some of these are quite expensive in relative terms but many amateurs are willing to shell out for them because they deliver consistently good results. My own journey took me in a different direction though. Instead of investing in a top-class laser collimator, I re-discovered the virtues of traditional techniques involving the collimation cap and Cheshire eyepiece.

My personal motivation to return to traditional, low-tech tools was stoked more from a desire to understand Newtonian telescopes more than anything else. Any ole eejit can use a laser collimator but it deprives you of attaining a deep understanding of how Newtonians operate. In addition, I have frequently found myself dismantling whole ‘scopes in order to get at the mirrors to give them a good clean and this meant I had to learn how to put them back together from scratch. The simpe collimation cap has been found to be an indispensable tool in this regard, allowing one to rapidly centre the secondary mirror in the shadow of the primary.

Singing the virtues of simple tools, such as the tried and trsuted collimation cap.

Using just this tool, I’ve been able to set up all my Newtonians rapidly to achieve good results from the get go, at both low amd medium powers more or less routinely.

For the highest power applications more accuracy is required and I have personally found that a quality Cheshire eyepiece to be more than sufficient to accurately align the optics in just a few minutes. Not all Cheshires are created equal though; some are less accurate than others. For my own use, I have settled on a beautifully machined product marketed by First Light Optics here in the UK ( be sure to check out the reviews while you’re at it). For the modest cost of £37, I have acquired a precision tool to take the hassle out of fine adjustment. The unit features a long sight tube with precisely fitted cross hairs that are accurately aligned with the peep hole. It needs no batteries and comes with no instructions but with a little practice, it works brilliantly!

The beautifully machined and adonised Cheshire eyepiece by First Light Optics, UK.

A nicely finished peep hole.

The precisely positioned cross hairs on the under side of the Cheshire.

Because all of my Newtonians are of the closed-tube variety, they are robust enough to only require very slight tweaks to the collimation. I would estimate that 80 per cent of the time, it is only the primary mirror that requires adjusting in field use. I have found this overview by AstroBaby to be very useful in regard to using the Cheshire and would recommend it to others.

The Cheshire eyepiece is a joy to use when collimating my 130mm f/5. Because the tube is short, I can access both the primary and secondary Bob’s Knobs screws to whip the whole system into alignment faster than with my laser. With my longer instruments; partcularly my 8″ f/6 and 12″ f/5, collimation using the Cheshire is decidely more challenging as they both have longer tubes. That said, by familiarising one’s self with the directions of motion executed with the three knobs on the primary, one can very quickly achieve precise collimation. One useful tip is to number the knobs individually so that you can dispense with the guesswork of which knob to reach for to get the requisite adjustment. At dusk, with the telescopes sitting pretty in their lazy suzan cradles, and with the Chesire eyepiece in place in the focuser, I swing the instrument back and forth to alternately view the position of the primary in the eyepiece and the knob(s) I need to turn. Doing this, I get perfect results in just a few minutes; a little longer than can be achieved with a laser, admittedly, but not long enough to render the process exhausting or boring. It’s time well spent.

Know thy Knobs: by spending some time getting to know which directions each of the collimation knobs move the primary mirror, it makes collimation with a Cheshire eyepiece hassle free.

The proof the pudding, of course, is in the eating, and in this capacity, I have found the Cheshire to achieve very accurate results each time, every time. Indeed, it has made my laser collimator blush on more than a few occasions, where high power star tests and images of close double stars reveal that the laser was out a little, requiring a collimation tweak under the stars. Indeed, the Chesire is so accurate that it has become my reference method to assess the efficacy of all the laser collimators I’ve had the pleasure of testing.

While I fully acknowledge the utility of good laser collimators, I get much more of a kick out of seeing, with my own eyes, how all the optical components of the Newtonian fall into place using the Cheshire. Furthermore, the fact that it requires no batteries (and so no issues with the unit failing in the field for lack of power, as has happened to me on more than a few occasions), deeply appeals to my longing for low-tech simplicity in all things astronomical. The fact that the aforementioned amateurs also recommend the Cheshire as an accurate tool for collimating a Newtonian makes it all the more appealing.

Having said all this, the utility of a Cheshire eyepiece lessens as the f ratio of your telescope gets smaller, so much so that for f/4 ‘scopes ar faster, the laser technique will, almost certainly, yield more accurate results. But that’s OK. We are blessed in this day and age with many good tools that can make Newtonian optics shine!

Note added in proof: August 14 2018

A really good laser collimator: the Hotech SCA, which can be used with both 1.25″ and 2″ focusers and comes in a very attractive little box with straightforward instructions on how to use it. You will still need the collimation cap to centre the secondary though.

If you do decide that you don’t like using a good Chesire eyepiece for precise collimation of your Newtonian reflectors, then I would highly recommend the Hotech SCA laser collimator. It’s an ingenious device (but costs significantly more than a regular laser collimator), but in this case you really do get what you pay for. I have tested the device on all three of my Newtonians and it gives accurate and reproducible results that agree perfectly with the Chesire. It yields perfect star tests at appropriately high powers (I’d recommend a magnification roughly equal to the diameter of your mirror in millimetres for such field tests) both in focus and defocused. I’d go for it if you can afford it. You will still need the collimation cap to centre the secondary before use however. See here and here for more details.

Neil English is author of Choosing and Using a Dobsonian Telescope.

De Fideli.

Focusing on Focusers.

Posted on 01/08/2018 by Neil English

How to adapt the Skywatcher 200P focuser to attain better collimation, as well as easier inter-change between 1.25″ and 2″ eyepieces.

Newtonians are tinkerers’ telescopes; they appeal to amateurs who want to learn about optics and above all other designs, they respond well to a bit of TLC. Such is the case with my modified Skywatcher 8″ f/6 Newtonian, which I have steadily improved over the last few years to transform it into my dream telescope; a modest instrument that can do all things well, from ultra-high power double star observing, through lunar and planetary studies and onwards into wide-field, deep sky observing. If I had to own only one telescope from all the varieties that now exist, I’d choose this one in a heartbeat.

The best way to improve a telescope is to spend as much time with it in the field. How else can one even begin to understand whether or not an alteration is warranted? In this capacity, I have clocked up hundreds of hours under the starry heaven inter-changing two inch, long focal length eyepieces for their shorter focal length counterparts, which are invariably in the 1.25″ format. But doing this in the usual way is frankly a bit of a chore. On my telescope, one has to remove the 1.25″ focuser housing, insert a two inch tube adaptor and then plonk in the big 2″ eyepiece. As you can imagine, this can get a bit fiddly on a dark night and cause needless interruptions to one’s observing schedule. Can this interchange be speeded up? Thankfully, the answer is yes!

The standard 1.25″ eyepiece adaptor that comes with every Skywatcher 200P Dob.

The first thing I did was to remove the standard 1.25″ eyepiece adaptor that comes with the telescope and replace it with an inexpensive 35mm extension tube, such as the one featured in the first image of this blog.

Next, I inserted an old Orion precision centring adapter into the 35mm extension tube, as illustrated below:

A very useful adapter: the Orion precision Centering Adapter seen inserted onto the top of the 35mm extension tube.

The precision centring adapter features a helical tightening mechanism that precisely centres any 1.25″ eyepiece in the focuser draw tube. This has immediate benefits to attaining ultra-precise collimation, as it removes the remaining wiggle room that would normally attend the insertion of a laser collimator in the standard 1.25″ eyepiece adapter.

Using the precision centring adapter improves the accuracy of collimation using a laser collimator or Cheshire eyepiece.

Once collimated, one can insert a 1.25″ eyepiece as shown below:

The centring adapter keeps 1.25″ oculars snug and precisely centred in the focuser drawtube.

To use 2″ eyepieces all one needs do is remove the centring adaptor, and insert the eyepiece into the 35mm extension tube as shown below:

Removing the centring tool is child’s play and allows for rapid interchnage with a 2″ ocular.

Testing this new system out during the day, I can report that it allows all my eyepieces; orthoscopics, Plossls, super-wide, ultra-wide angles and even Kellners to reach sharp and precise focus at infinity, as well as targets located as close as approximately 50 yards in the distance. It greatly facilitates the inter-change between 1.25″ oculars and their 2″ counterparts in the field because it always has the 2″ eyepiece adapter in the focuser drawtube. No more fumbling about in the dark.

So, if you’ve got these adapters lying about in your ole box of tricks, I’d encourage you to give it a go. It can only serve to increase your enjoyment of a very fine telescope. You know it’s worth it!

Octavius: working more efficiently for its master.

Note added in proof (August 2 2018): I’ve managed to get out on a few nights before the weather turned and test the new configuration on both my 8″ f/6 and 12″ f/5 instruments (both of which are endowed with 2-inch focusers) under rapidly darkening skies. I can report that the alteration was definitely worthwhile!. The centring adapter is very easy to remove or insert at will, allowing me to go from wide-field scanning at low power, using heavy, 2-inch eyepieces covering a couple of angular degrees of sky or more, and then zoom in at inceasingly high powers, sometimes much beyond 50x per inch of aperture, to look at high resolution stuff.

All in a jiffy!

One downside noted: some(but not all) Barlowed oculars can’t come to focus with this modus operandi.

No’ bad ken.

Neil English is author of Choosing and Using a Dobsonian Telescope.

De Fideli.

Sampling the Skies in Ireland with a 5.1 inch Newtonian.

Posted on 23/07/2018 by Neil English

Plotina: the author’s 130mm f/5 travel Newtonian enjoying the skies over Cork Habour, Cobh, County Cork, Ireland.

July 9 through 21, 2018

It could have been altogether very different.

Having access to a suite of small, portable instruments, like a fine 90mm ED refractor, a first-rate 80mm f/11 achromat, an ETX 90 and a 90mm f/10 achromat, I’m so glad I threw tradition to the wayside and brought along my 130mm f/5 Newtonian telescope on my recent trip to Ireland. As described exhaustively in several previous blogs, the latter instrument is a superior grab ‘n’ go telescope to all of the above instruments on all targets; whether in the Solar System or far beyond. Its mirrors efficiently bring light to a sharp focus and with a relatively small central obstruction (27 per cent), it behaves more like a 5 inch refractor than anything else. Yet it is very lightweight, easy to collimate accurately and, as demonstrated previously, delivers excellent images of planets, the Moon and very tight double stars down to 0.94 seconds of arc: the absolute limit imposed by its 130mm aperture. And, as will be described shortly, it’s not too shabby as a rich field/deep sky instrument either.

These findings were all previously established in many parts of the Scottish mainland and even on some of the Western Isles, but I was especially keen to see how the telescope would fare at no less than five locations in Munster, the southern-most province of the Irish Republic. I have very fond memories from youth using much smaller instruments, but the 130mm Newtonian promised to reveal much more.

The Journey

The telescope was carried in a sturdy aluminium case in the boot of my car from my home in central Scotland down to southern Scotand, and then by ferry across to Northern Ireland, and from there, southwards to the Republic; a day’s trip.

Upon arrival, the telescope was found to be very slightly out of collimation but a laser collimator made light work of tweaking the optics in a matter of seconds.

Locations tested:

Limerick City: Ballinacurra in the southwest of the city & Caherdavin, a few miles away on the other side of the great River Shannon, in the northwest of the city.

Cobh, County Cork.

Sixmilebridge, County Clare.

Newport, County Tipperary.

Conditions: Over ten days, only two nights turned out cloudy, the rest being either fully clear or partially clear. At all locations, true darkness occurred around local midnight, remaining so for about two hours. In general, all observations were conducted on grass, as this was established to be the best surface upon which astronomical observations should be made.

Eyepieces used: Just two oculars were chosen for the trip; a Celestron X-Cel 25mm, delivering a power of 26x in a 2.3 degree true field, and a Meade Series 5000 5.5mm ultra wide angle, serving up a power of 118x in a 0.7 degree true field. Additional powers of 59x and 266x could be pressed into service by attaching a Baader 2.25x Baader shorty Barlow to the 25mm and 5.5mm eyepieces, respectively.

Telescope mounting: The 130mm f/5 is a perfect match for the Vixen Porta II Alt-azimuth mount, which travelled with me along with the telescope. High magnification targets were tracked with ease using the in-built slow motion controls.

Results on the Planets: Planetary views of Jupiter and Venus were conducted earlier in the evening. Mars was not viewed owing to its very late culmination well into the wee small hours of the morning. The extra 4 degrees of elevation in the sky owing to the sites’ lower northerly latitude (centred around 52 degrees north), proved significant; Jupiter showed a wealth of detail using the 5.5mm Meade ultrawide angle ocular delivering 118x. Much dark banding and subtle colour differences within the bright zones could be discerned. The North Equatorial Belt (NEB) was very prominent throughout all the vigils, being noticeably darker and more disturbed morphologically than its southern counterpart. On one evening, I was able to accurately establish the CM II longitude of the Great Red Spot and the finest images of Jupiter were afforded at Newport, County Tipperary, with the telescope set up on tarmac owing to a lack of a suitable grassy surface, but the relatively high elevation of the shorttube 130mm reflector astride the Viven Porta II above the surface proved an effective dampener of thermals, even though the same day and evening were hot and sunny.

Venus showed its pretty, early gibbous phase at 118x in the telescope, despite its very low altitude at the times of observation. Some atmospheric refraction yielded some false colour but this was expected and largely unavoidable.

The Moon:

On Thursday, July 19, I shared some magical moments with my elder brother, who lives in Newport, County Tipperary. Around sunset, I set the instrument on the tarmac ouside his house and aimed it at a late crescent Moon. The view in the 5.5mm Meade delivering 118x was amazing; my brother being deeply impressed at seeing the entire lunar regolith in razor-sharp detail, floating through the huge portal hole. At first he couldn’t help but hold the eyepiece (a natural newbie reaction), but as soon as I taught him to let go, he just relaxed and let the telescope do the work. I could tell that he was quite taken aback with this strange little telescope, where you peer through its side rather than directly along the tube. With a few minutes training, he learned how to use the slow motion controls to bring Luna back into the centre of the field.

Double Stars:

Test double stars examined included:

Epsilon Bootis ( Izar)

Delta Cygni

Epsilon 1 & 2 Lyrae

Pi Aquilae

Such systems were chosen for their sensitivity to ambient seeing conditions and ease of location, even from an urban/suburban setting.

Results: At every location examined, the results proved very much the same: all systems were beautifully resolved at 266x, the companions being perfectly picked off from their respective primaries. One location proved to be windy (overlooking Cork Harbour in Cobh), but this turned out to be largely inconsequential to the observations made. Once the wind died down, the companions yielded easily.

Deep Sky Observations:

General appearance of the sky after sunset, as witnessed on a few evenings during the vacation. Such cloud formations augur good, stable summer air.

Naked Eye: I immediately noticed the lower elevation of the Pole Star than at home.

I recorded three bright fireball-like meteors streaking across the sky (2 on one evening, the other on a subsequent evening) from the direction of Cassiopeia/Perseus. These were possibly early Perseid meteors, which will culminate around the middle of August.

Even from a suburban location (Caherdavin), the sky got dark enough to easily see magnitude +4.6, Iota Cassiopeiae, low in the northeast, which was not possible from my Scottish vantage owing to the encroach of twilight. From the same location, I was able to trace out the more prominent parts of the Northern Milky Way streaming through Cygnus and Cassiopeia.

The darkest skies were experienced at Cobh, which is not too surprising, but there was still a significant amount of light pollution from the adjacent harbour to the southwest of my viewing location. Still, magnitude +5.8 Messier 13 could not be seen owing to this light pollution despite its high elevation in the southwest at the times of observation.

Telescopic Impressions:

The 5.1 inch reflector set up for an observing session at Sixmilebridge, County Clare.

The 25mm Celestron X-Cel LX eyepiece proved very satisfactory with the 130mm f/5 reflector, delivering sharp, high-contrast images of star fields nearly all the way to the edge of its 2.3 degree field. I enjoyed studying the stellar hinterlands of bright stars within Cygnus, particularly Sadr and Deneb, the truly dark skies pulling out a wealth of fainter stars frankly invisible in the twilight of Scotland.

M39 in northern Cygnus was pariticularly captivating in the 25mm wide field eyepiece at Caherdavin; a rich smattering of approximately three dozen suns of the 7th magnitude of glory and fainter, arranged in a neat triangular space approximately 30′ in size. The Barlowed view with the same eyepiece at 59X was much more immersive though. M29 was dull in comparison; small wonder my guide book has nothing to say about it lol!

The 5.5mm Meade ocular was by far my most used ocular during the trip. Having become somewhat disillusioned by high-quality, small field of view oculars, such as the Vixen HR series, with their measly 40 degree fields, I very much appreciated the vastly more expansive (yet very well corrected) fields afforded by this 82 degree ocular. Such short focal length, wide-angle eyepieces are a godsend to those who enjoy manually tracking tight doubles. They are visible for longer, allowing the observer much more time to examine their morphology before having to nudge the telescope along.

The 5.5mm served up excellent, immersive views of showpiece summer deep sky objects such as M13, M92 and M57, the 118x power really helping to darken the sky. The view of M13, in particular, was most impressive, even from suburban locations, comparing very nicely with my 5″ f/12 refractor from my recollections. The outer part of the globular was well resolved with dozens of stars seen directly or by using averted vision.

The same eyepiece is especially good at observing wide ‘binocular’ doubles such as Albireo, 61 Cygni, Gamma Delphini, Beta Lyrae and the incomparable 31 (Omicron) Cygni, all of which were enjoyed with the telescope at most of the sites visited.

At 23:30 UT on the evening of July 16, I aimed the telescope from suburban Limerick (Caherdavin) at Iota Cassiopeiae, then located just above the tree line of the garden. To my sheer delight, I was able to clearly see the three components of this trple system using the Meade ocular at 118x. This was a particularly impressive observation, owing to the fairly low power employed but also because of its low elevation at this site. This is a powerful testimony to the excellent stability of Irish suburban skies.

I enjoyed some special time exploring the rich treasures of the far northern constellation of Cepheus on the evening of July 16, which is drowned out by twilight in Scotland. Delta Cephei was very captivating at 118x. The primary is an old, yellow pulsating Cepheid variable( the prototype of this stellar class) with a gorgeous blue companion; a near twin of the more famous Albireo. Xi Cephei presented beautifuly also; its blue white and yellow suns well resolved at 118x. Omicron Cephei was also briefly visited; easily resolved at 118x but better seen at 266x; its magnitude +4.9 ochre primary and much fainter (magnitude +7.3) steely grey companion being readily observed. Then, there is the incomparable Mu Cephei, an enormous red giant star, its deep sanguine hue standing out like a sore thumb against a good, dark sky was a sight for sore eyes. Mu is comely at low or high power in the 130mm reflector.

Don’t forget Saturn!

Almost forgot!

Though it was past their bedtime, I showed my boys the planet Saturn for the very first time, located well east of Jupiter and only becoming visible to the naked eye very late in the evening. Being even lower in the sky than brilliant Jove, the telescope still did a mighty good job at 118x showing them the mottled globe of the planet, with its beautiful, icy-white ring system, the Cassini Division being easily dicsernible at a glance. The view at 266x was not so good though; a simple consequence of the blurring effect of the Earth’s atmosphere at this low altitude. Still, I showed off Saturn to friends and family where ever possible. Of all the celestial objects studied, it was the Ringed Planet that received the most oohs and aaws!

Concluding Thoughts

The experience of a truly dark sky in mid-July was a joyous event for me; accustomed as I am to ferreting out things to see in twilight at home in Scotland. The small Newtonian proved to be the perfect travelling companion, its generous aperture, light weight and easy set-up all helped to make the trip memorable and worthwhile. In many ways, Ireland is a transformed nation now (it would be naive not to think so); sadly, it has sleepwalked its way into the pernicious mire of secularism, with all its attendant depravities. But at least the skies overhead are still good to go, a comforting reminder of God’s incomparable glory and omniprescence. Though I would like to have visited a site completely devoid of light pollution it was not to be on this occasion, yet conditions were near ideal during these eight days of observations (especially for high-resolution, double star work), but surely many more such evenings occur on the Emerald Isle?

And I’d do it all again in a heartbeat!

Neil English is author of a large and ambitious work; Chronicling the Golden Age of Astronomy, due out later in 2018.

De Fideli.

Going from Strength to Strength: the 130mm f/5 Newtonian.

Posted on 02/07/2018 by Neil English

Plotina: queen of grab ‘n’ go ‘scopes.

I’ve spoken quite extensively on the considerable virtues of my modified 130mm (5.1- inch) f/5 Newtonian with a 27 per cent obstruction. In contrast to the prognostications of fake theorists and arm-chair amateur astronomers, it has proven to be a fantastic all-round ‘scope, easily trouncing smaller grab ‘n’ go refractors and equivalent sized Maksutovs costing significantly more. It provides very pleasing wide field views at low magnification and excellent performance at high magnifications, especially on a suite of double stars, the Moon and bright planets.

As a double star enthusiast, I have managed to split systems down to one second of arc with this telescope during the winter months but in theory it ought to do a little better. Specifically, the classic Dawes limit for this aperture is given by 4.57/5.1= 0.89″ but is confined to pairs which are reasonably matched in terms of brightness. In this capacity, I was curious to see whether I could resolve the very challenging Lambda Cygni, with a current separation of 0.92″, the components of which differing only by 0.4 stellar magnitudes(5.4 and 5.8).

Taking full advantage of the hot, settled spell (Scorchio lol!) that is currently being enjoyed by residents of the British Isles, I eagerly sought out a system I’ve visited many times before, but mainly with my larger instruments (8″ f/6 and 12″ f/5 Newtonians). I speak of course, of that easily accessible system riding high in my summer sky after midnight during June evenings; Lambda Cygni.

This magnitude 4.5 system is easy to track down, even in twilight, and in preprartion, I have been monitoring an easier system; Pi Aquilae, located much lower down in the east south east at this time. My reasoning was simple; if this lowly system was well presented at high powers in the 130mm instrument, there would be a decent chance that Lambda Cygni would also bear fruit. But that proved to be easier said than done. Over several nights, both this week and last week, I have carefully studied the system but invariably recorded strong elongation. Yet in double star observing, as in so many other arenas of human enquiry, it pays to persevere; and finally in the wee small hours of June 27 2018, I won my prize!

At half past midnight, I noted an exceptionally stable and well resolved Pi Aquilae at powers of 260x and 406x and excitedly turned my telescope on Lambda hoping for a better result. And at 2 minutes past 1am local time, it yielded. Letting the system drift through the field several times over a period of a few minutes I could make out two distinct Airy disks intermittently separated by a delicate sliver of dark sky using a power of 406 diameters!

To put this in context, I have previously just resolved this system using a fine 127mm f/12 achromatic refractor at very high magnifications. And though my recollections show that it was that little bit better at ferreting out the pair, it was always very challenging and only possible under similarly clement conditions. So a most satisfactory result, but not at all violating the rules of classical optics. If something is possible, it will happen; you just have to be there to experience it!

I made a drawing of what I observed at the eyepiece( shown below);

Shumbody stop me!

I’ve been thinking about the eyepieces I wish to bring on our summer vacation and decided to treat myself to an upgrade to my trusty 32mm Plossl. To that end, I gravitated toward the Explore Scientific 24mm 68 degree ocular, which would provide a power of 27x in a 2.5 degree field (the maximum possible for a 1.25″ focuser). So I ordered one up for the princely sum of £142 plus shipping. I had very high expectations about this eyepiece judging by the excellent performance of two other 68 degree Maxvision oculars ((34mm and 40mm also marketed by Explore Scientific) I have already field tested. Both of these provide very highly corrected fields across a very expansive field and provide excellent eye relief for maximum viewing comfort. The eyepiece was ordered on Monday June 25 and it arrived in the early evening of June 27.

The Explore Scientific 24mm 68 degree ocular.

As soon as it was getting dark, I fielded the 130mm f/5 Newtonian once again in order to test the new eyepiece out. Centring Vega in the field, I focused the image and to my chagrin, I noted pretty harsh field curvature and coma in the outer part of the field. When Vega was sharply focused at the edge of the field, the stars in the periphery of the field were quite badly out of focus. This was patently not the result I expected for such a pricey eyepiece. What is more, the eye relief was pretty poor too. I had to bring my eyeglasses right up to the field lens, with the ruuber eyecup pushed down, to try to take in the entire field but it was barely possible and far from comfortable. “As tight as a knat’s chuff” is an expression that immediately sprang to mind lol!

When I compared it to my 32mm, the eye relief was far more comfortable (being about 0.73 times the focal length in millimetres, so ~ 23mm) and though the magnification was slightly lower (20x) the Plossl proved significantly better corrected at the edge of the field!

Was I disappointed? You bet I was! I don’t know if I received a lemon or not but on the morning of June 28 2018, I phoned the dealer and explained that the eyepiece did not perform as advertised and that the 32mm Plossl I tested alongside it delivered better performance. Thankfully, they gave me the go ahead to send the eyepiece back so they could test the unit out. I expect a full refund in due course.

What a palaver!

Anyway, while thinking about my next move on the low power eyepiece front, I intend to bring my trusty 32mm Plossl on my vacation, together with my old Mark III 8-24mm Baader Hyperion zoom. This will provide all the medium power viewing I will likely do, and the 2.25x Baader Barlow will enable me to increase the power to 183x; good enough to study quite a few double stars under dark, Hibernian skies.

Travelling light ( from left to right); my 32mm SkyWatcher Plossl, 8-24mm Baader Hyperion zoom and dedicated 2.25x shorty Barlow.

After several more nights of observation with the 130mm f/5 Newtonian, I managed yet another sighting of the companion to Lambda Cygni. Specifically, on June 30 at 23:20 UT, using the same power of 406x, the stars were seen cleanly separated on and off during several minutes of observations. With the fine weather continuing for UK observers, I would warmly encourage others with instruments of 5 inches and over to have a go at this system at high powers. It’s very accessible with an 8″ f/6 Newtonian (confirmed once more around local midnight on July 1/2)

The Explore Scientific eyepiece arrived safely back at the dealers this afternoon (July 2 2018). I am now considering the Celestron 25mm X-Cel LX, which is purported to work well in f/5 optical systems and with a 60 degree AFOV should give nice, expansive views, well over 2 degrees in extent.

July 4th 2018: A Very Happy Independence Day to all my viewers in the Colonies!

We leave for Ireland on Monday next, July 9. I’m very excited about sampling the skies of my youth with my 130mm f/5. Of course, I’ve had other telescopes over there, back when my folks were still in the land of the living; a 90mm f/10 achromat (which is still at my sister’s home), and when the ETX 90 was all the rage in the late 1990s, I astounded my late father with its go-to capability and almost magical ability to centre and track down the planet Jupiter in the field of view one chilly Christmas Eve.

Plotina being readied for another night of sky gazing.

Bringing a Newtonian is a big change for me. It was always a small refractor or Mak that made it, but this time ’round, I can think of no better telescope to enjoy my vacation with. My wife got a bit of shock when I told her I’d be lugging the 130 in its case, but she has since come round to the idea of having me put all my astro junk in one neat place lol..

I’m relatvely new to Newtonians you see. I pretty much overlooked them, owing to the rise of refractor mania and catadioptrc telescopes in the last few decades. I did have one in my youth however; my second telescope, a Tasco 114mm (4.5-inch), f = 900mm or some such that came in a big yellow box decorated with fabulous photos of planets and deep sky objects. Back then though, I knew next to nothing about the rigours of fine collimation, or how to precisely align its equatorial mount(non-motorised). I bought it second hand from a jeweller that lived near me. It cost me £100; an enormous sum of money for a young teenager in the early 1980s. I eventually sold it on to raise some funds for University a few years later.

Still, the 130mm is far superior in many ways to that old Tasco; greater aperture, light gathering power and sharper optics owing to its nicely figured parabolic mirror. No fooling around with complex mounts either; just stick it on the Vixen Porta II and I’m off to the races! Eyepieces have improved vastly as well; the Tasco came with two cheap Huygenians and a junk Barlow lens.

Mars’ fiery red mien graces my horizon after midnight and Jupiter is quite a bit past opposition, but I hope to get a better view of both worlds as they will rise a few degrees higher in the sky than they do here in rural central Scotland. And having the chance to explore the vast skyscape within the confines of the Summer Triangle (marked by Vega, Deneb and Altair) from a truly dark sky will be an enjoyable experience. That said, last night I lingered a while on a reasonable view of the Ring Nebula in Lyra with my 34mm widefield and 8-inch reflector in summer twilight. How much better will the views be under true July darkness?

I decided to pull the trigger on a Celestron X-Cel 25mm LX eyepiece, which should arrive here by Friday. Fingers crossed for reasonable performance in the f/5 optical system!

The sky is darkening more now as the days and weeks have flown by the Solstice. The stars of Delphinus are beginning to show in the deep twilight and so a chance to visit another summer favourite; the delightful colour contrast pair, Gamma Delphini.

After midnight on July 5 2018, I began searching for two systems; Gamma Delphini and Mu Cygni. The latter proved much more challenging to track down, even with the Celestial Swan now having gained a considerable altitude. Gamma is widely spaced and presents with an aureal primary and lemon-white secondary. Mu is much more challenging though, especially at this time of year; the secondary is situated right up next to the primary but the great light gathering power and resolution of this grab ‘n’ go telesope on steroids made light work of it at 260x but the view was even more compelling at 318x. It’s such a delicate system to study telescopically; like budding yeast seen through a powerful microscope. I made a couple of drawings of what I saw (shown below):

Two gems of the summer twilight: Gamma Delphini & the challenging Mu Cygni, as seen through the 5.1″ f/5 Newtonian in the wee small hours of July 5 2018.

July 6 2018

The Celestron 25mm X-Cel LX 60 degree eyepiece.

Well, the new 25mm Celestron X-Cel LX eyepiece arrived late this evening. It was packaged well and a quick inspection revealed no internal dust in the optical train. It is very light, considerably less so than the 24mm Explore Scientific (ES) 68 ocular I sent back to the dealer and that’s a bonus, given the low mass of the optical tube. Like the Baader zoom, this eyepiece has a twist-up eyecup which allows the user to adjust the distance between the large eye lens and the eye. Testing it on the telescope in the bright evening sunshine revealed some very good things; the image of a distant rooftop was very sharp. Constrast was excellent. It showed a very small amount of field curvature and/or distortion at the edge of the field but best of all the eye relief was just right; that is, I was able to comfortably view the entire field with my eyeglasses on, in sharp contradistinction to the ES 68. Things were indeed looking good.

The Celestron 25mm X-Cel eyepiece has a large eye lens and twist-up eye cup for optimal viewing pleasure.

Around local midnight, I was able to test the new eyepiece on the stars. I am happy to report that it produced very sharp images of Vega and its hinterland, with good contrast and, to my relief, off axis performance was much better than I had experienced with the 24mm ES 68. Nor did I detect any internal reflections. There was a liitle distortion at the edge of the field but it was more than acceptable, certainly a notch up from the 32mm Plossl I have used for so long with the instrument. And like my daylight experiences, the eye relief was more than adequate when used with my eye glasses(which corrects for the natural astigmatism in my viewing eye). This improved perfomance may at least in part be attributed to the smaller AFOV of this eyepiece (60 degrees as opposed to 68 degrees with the 24mm ES) but maybe also to its design differences. Nevertheless, I am more than content with its optical performance as a low-power, wide-field scanning ocular, delivering a power of 26x in a true field of 2.3 degrees. And in consideration of the fact that it set me back just half the price of the 24mm ES 68 (£70), I think it represents a really good bargain.

Technology has come a really long way since the days of my youth.

A happy camper am I.

At 00:45 local time on Saturday July 7, I turned the telescope toward Cassiopeia, now low in the northern sky and washed out quite a bit by the presence of twilight. I used my 6 x 30mm finder on the 130 to track down the creamy white magnitude +4.6 star, Iota Cassiopeaie. Ordinarily, I wouldn’t go near such a system at this time of year owing to how bright the sky is, but the persistant good weather here inspired me to give it a go. From memory, this star is annexed to a triangular configuration of three fainter stars so it was easy to identify. This is a famous triple system and its delicate cast under good conditions never fails to impress. I was pleasantly surprised with how well it presented at 260x, with all three members showing up clearly and distinctly. I made a quick sketch of what I recorded in the small Newtonian telescope, and is shown below. This is well worth a try at high northern latitudes in small telescopes with easy access to the northern horizon.

Iota Cassiopeiae as seen at 23:45 UT on the night of July 7th 2018 using the 130mm F/5 Newtonian at 260x. Note that the date should read July 7 and not July 10. Mea culpa.

I spent the afternoon of July 7 2018 deliberating about which eyepieces to bring and which to leave behind. The new 25mm Celestron is definitely coming on the trip. Further daylight tests showed that it Barlows real well with the 2.25x Baader shorty Barlow giving a nice medium power of 59x in a one degree true field. I have had second thoughts about the Baader zoom though, as it’s a bit on the heavy side and even with the same Barlow would only yield 183x, grand for most systems but since the telescope can very comfortably accommodate 50x per inch of aperture, I wished to coax that little bit more power out of the instrument. Racking my brains, I pulled out an older eyepiece which I had boxed away under my bed; a Meade Series 5000 5.5mm Ultra-Wide Angle (82 degree field). As I’ve said in a previous blog, I’m not overly enamoured by 82+ degree AFOV oculars, preferring 60 to 70 degree units in my field work, but upon testing it out in the 130mm f/5 Newtonian on a bright sunny day, I was quite impressed with what it delivered. A high-end eyepiece like this has very good edge-of-field correction and yields a power of 118x in a field of 0.7 degrees. Coupled to the 2.25x Barlow I can squeeze a high power of 266x out of it; perfect for the most challenging doube stars should they present themselves!

So, in the end, two eyepieces, both significantly lighter than the Baader zoom, will be coming on the trip with me, together with a single, 2.25x shorty Barlow. That combination will tick all the boxes!

Final choice (left to right): the Celestron 25mm X-Cel LX, the Meade 5.5mm Ultra Wide Angle and the 2.25x Baader short Barlow lens.

This is a good place to wrap up this blog. Take care and see you all when we get back in a couple of weeks.

All the best,

Neil.

De Fideli.

Observing in Twilight.

Posted on 22/06/2018 by Neil English

A great ‘scope to use in twilight; the author’s 130mm f/5 Newtonian which combines light weight with good optical power.

At my northerly latitude (56 degrees north) every year from about the middle of May to the first week in August, the sky fails to get properly dark and twilight dominates the northern horizon. As a result, the glory of the summer night sky greatly diminishes, with only the brightest luminaries being visible to the naked eye. But despite these setbacks, one can still enjoy a great deal of observing. In this article, I wish to outline some of the activities I get up to during this season.

Observing in twilight makes observing faint deep sky objects very difficult, so my attention is drawn to the Moon, brighter stars and the planets. Although a telescope of any size can be used during twilight observing, I find it most productive to field a telescope that has decent aperture and so I generally reach for my larger telescopes. Arguably my most used instrument during these times is a simple 130mm f/5 Newtonian, which offers good light grasp and resolution but I am also very much at home with my larger 8 and 12 inch reflectors for more specialised work. The 130mm has the advantage of being light and ultraportable and so I can move the instrument around to get better views of low lying targets.

The bright planets are very accessible during twilight and I find it fun to observe them with a variety of instruments. Venus is generally uninspiring, showing only an intensely white partial disk, but I find Jupiter much more exciting owing to its constantly changing atmospheric features and satellite configurations. But because of its low altitude in my sky, I employ colour filters to bring out the most details on the planetary disk. This is where larger apertures have their advantages, as some filters can absorb a significant amount of light and dim the images too much. The sketch below was made during twilight using my 130mm f/5 and a Tele Vue Bandmate planetary filter, power 108x, which imparts a lively colour tone to the planet, enhancing the colour differences between the dark belts and light zones. It’s also an ideal filter for enhancing the visibility of the Great Red Spot(GRS).

Jupiter as observed durng twilight at 22:55 to 23:05 UT on the evening of May 28 2018 using a 130mm f/5 Newtonian, magnification 108x and a Televue BPL filter.

Twilight nights are also excellent for double star work and summer often brings prolonged periods of excellent seeing at my location. Larger apertures allow higher magnifications to be pressed into service, which also helps to darken the sky making the views more aesthetically pleasing. As in all other aspects of amateur astronomy, you can be as ambitious as you want. The most demanding systems are difficult, sub arc second pairs. As a case in point, I recently trained my 8 inch f/6 Newtonian on 78 Ursae Majoris (78UMa), conveniently located near the bright star, Alioth, in the handle of the Ploughshare. Conditions were near ideal on this evening (details provided in the sketch below) and I was able to push the magnification to 600x to splice the very faint and tight secondary star from the brighter primary.

The sub arc second pair 78 Ursae Majoris 78 as seen in twilight on the morning of May 30 2018 at 23:20UT using an 8″ f/6 Newtonian reflector (no fan).

Another system that I like to re–visit in summer twilight is Lambda Cygni (0.9″), which is easier to resolve than 78UMa, as the components are more closely matched in terms of their brightness and are slightly farther apart. Because it rises very high in my summer sky, it is ideally placed for high magnification work.

Conducting sub–arcsecond work with an undriven Dob mount is certainly not for the faint hearted but does bring its unique challenges, and I for one get a buzz out of doing this kind of work. But there are many easy and visually stunning systems that can be enjoyed at lower powers and it is to some of these that I will turn my attention to in the coming nights.

Last night (the early hours of June 2 2018) my wonderful little 130mm f/5 Newtonian was used to visit a number of easy to find and visually engaging binary and multiple star systems. During warm, settled weather, and with high pressure in charge, the twilight conditions proved near ideal for studying these fascinating objects;

Some binary systems visited in twilight using a 5.1″ f/5 Newtonian.

The celebrated Double Double in Lyra as seen through the 5.1 inch reflector at 260x.

The very fetching Epsilon Bootis as seen in the 130mm f/5 Newtonian at 260x.

These observations were conducted between 23:00UT and 00:00 UT.

Indeed, of all my Newtonians, it is the 130mm f/5 that provides the most aesthetically pleasing views of double stars. Colours are always faithful and images are invariably calm owing to its moderate aperture and rapid acclimation. Contrast is excellent too. It just delivers time after time after time…..

The sky as experienced 15 minutes before local midnight on the evening of June 12 2018.

As May turns to June, the twilight becomes ever brighter, with more and more stars becoming invisible to the naked eye. But this greater sky brightness should never deter a determined observer. On the evening of June 12 2018, I set about visiting a score of double and multiple stars with my 130mm f/5 Newtonian, as is my custom. I turned the telescope toward Polaris at 22:45 UT and was deligted to be able to pick up the faint 8th magnitude companion to the 2nd magnitude Cepheid primary. Looking for something more challenging, I waited another half an hour to allow the sky to darken maximally but also to allow a summer favourite to gain a little altitude but still several hours away from culmination in the south. I speak of that wonderful binary system, Pi Aquilae( Aql), a pair of yellow white stars of near equal brightness and separated by about 1.5 seconds of arc.

From extensive, previous experience, I know it is possible to split this pair in smaller telescopes than the 5.1 inch reflector, particularly a suite of refractors ranging in aperture from 80mm to 102mm. But under these June conditions, the advantages of decent aperture become readily apparent; smaller telescopes simpy run out of light too quickly when the high powers needed to splice this pair are pressed into action. Locating the 6th magnitude pair at a fairly low altitude under bright June twilight is even a challenge for the 6 x 30mm finder astride the main instrument. To my delight though, I was able to track it down and once centred, I cranked up the power to 325x ( using a 2mm Vixen HR ocular) to obtain a marvellous view of this close binary system, the components aligned roughly east to west with clear dark space between them. Adopting these powers with smaller apertures is problematical to say the least. Why strain one’s eyes when one can view it in much greater comfort using the generous aperture of this trusty 130mm grab ‘n’ go ‘scope?

I made sketeches of both Polaris A & B and Pi Aql as I recorded them at the eyepiece (see below).

Polaris A & B and the tricky, near equal magnitude pair, Pi Aql, as seen in the 130mm f/5 Newtonian reflector on the evening of June 12 2018.

As the June solstice approaches, the twilight continues to brghten the sky, but there’s still lots to see. Beginning about 10pm local time, I began observing a pretty crescent Moon sinking into the western sky. The instrument I chose this evening was a very inexpensive but optically excellent 76mm f/9.3 Newtonian reflector, which I described at length in previous blogs such as this one. Because our natural satellite is so big and bright, a small telescope like this one is ideal for casual observing. Because the sky is still quite bright at this time, I found it helpful to employ either a neutral density or variable polarising filter to increase the contrast between the lunar regolith and the background sky.

An amazing performer in June twilight: the Orion Space Probe 3 altazimuth reflector.

Observing the Moon in June twilight is fun at all magnifications, but I have discovered this little telescope can provide razor sharp images up to about 210x. You’ll not get this information from the telescope forums though; it still seems beneath them to test it and spread the word, but I digress!

On the evening of June 18 2018, I visited a suite of summer double and multiple stars with the same instrument.

At about 11.30pm local time, the sky was dark enough to track down some pretty tight double stars, as well as a variety of easier but just as comely systems. Conditions were good enough for the little Spaceprobe reflector to nicely resolve Epsilon Bootis, Epsilon 1 & 2 Lyrae and Delta Cygni (210x in each case). My study of the Lyra Double Double in particular with this telescope shows that it is significantly better than any 60mm refractor in terms of raw resolving power. As I have reported earlier this year, the same telescope was able to resolve Xi Ursae Majoris, Porrima, Eta Orionis, and the wonderful triple system, Iota Cassiopeiae. Sadly, the latter system, which is still present low in the northern sky in June, was hopelessly lost in the summer twilight. Bootes always presents a nice playground for easy and pretty double stars, including Kappa, Pi, Xi and Nu 1 & 2 Bootis, which were all easily split at 116x.

June is also high season for the beautiful, ghostly whisps that meteorologists refer to as noctilucent clouds. These thin, high altitude formations are lit up by the Sun while still below the northern horizon, creating quite surreal visual delights to the naked eye. I took a couple of low resolution images with my iphone (shown below).

Noctilucent clouds captured outside my house at local midnight on the evening of June 18 2018.

Another view captured at local midnight on the evening of June 18 2018.

I shall endeavour to capture some higher resolution shots of these wonderful meteorological structures in due course.

Plotina, the author’s amazing 130mm f/5 Newtonian reflector as seen at 11.10pm on the evening of June 21 2018.

On the June Solstice of 2018, I walked through the garden in the cool of the evening, fetching my trusty Vixen Porta II mount to field my 130mm f/5 Newtonian. A gentle westerly breeze was blowing and the sky was resolutely clear, but I have learned on many past occasions that these conditions often bring very good seeing conditions for high resolution double star work. And my efforts were rewarded with text book perfect images of a suite of difficult double stars, some of which I have mentioned earlier in this report. I also ended my year long evaluation of a variety of eyepieces and Barlow lenses,varying quite considerably in price range. These studies have led to some firm conclusions regarding the effects of moving air upon Newtonian optics, as well as some very surprising results concerning the efficacy of certain oculars in regard to resolving double stars. Do you always get what you pay for? Most certainly not!

Insofar as artificiallly blowing air on a Newtonian mirror has been shown to scrub off the so-called boundary layer immediately above the reflective surface, my field testing over many nights shows that natural wind can also improve the images in exactly the same way. For this reason, I invariably point the telescope into any prevailing wind while the telescope cools and this works especially well for my larger Newtonian reflectors (8- and 12 inches). Furthermore, I am not aware of any historical precedent for this; the work of some notable telescopic ancestors of the ilk of W.F. Denning, T.H.E.C. Espin, T.E.R. Philips, A.S. Williams, T.W Webb and N.E. Green ( the selected work of which I will feature in my up-and-coming historical work) all of whom used Newtonian reflectors to great effect do not explicitly give mention to this result, though there is no doubt it is generally true.

The Vixen HR series of oculars; nice but totally overkill for high resolution double star work in medium and large aperture aperture Newtonian reflectors.

On many fine evenings using a variety of Newtonian telescopes, I have compared the views through top-of-the-range eyepieces, such as the new Vixen HR series of ultra-short focal length oculars(1.4mm, 2.0mm and 2.4mm) and those derived from much more modest (but still very good) Plossls and orthoscopics coupled to decent Barlow lenses and my conclusions are that the much more expensive eyepieces do not confer any real advantages over the latter.

Ordinary eyepieces and Barlows work perfectly well with Newtonian reflectors for high-resolution double star work. Left to right; a 3x Meade achromatic Barlow, a 7.5mm Parks Gold and Baader 6mm classic orthoscopic.

Yes, the HR series do display slighly better contrast and reduced light scatter compared to Plossls and orthoscopics but the differences were never enough to count. i.e. There was never an occasion where I could not see a tight companion in one over the other at comparable magnifications. Indeed, the HR series of eyepieces have very restrictive fields (42 degrees), even compared with the modest 50 degree fields offered up by a Plossl and/or the Baader classics (which have a larger 50 degree field) when Barlowed allow for significantly larger fields to be exploited. There is thus a distinct advantage to the using the far less expensive Plossl and orthoscopic type eyepieces over the HR series (the three of which will set the consumer back a hefty £750 UK), especially when employing a non-motorised altazimuth mount such as my Vixen Porta II.

Don’t believe the hype; binary stars are very simple, just tight little Airy disks. Save your money and use it more productively on other things.

Well, I hope you enjoyed this blog and that you don’t become discouraged observing throughout the twilight season wherever you live.

Thanks for reading.

Neil English’s new book, Tales from the Golden Age, uses history to debunk a few myths that have crept into modern amateur astronomy. Available in late 2018.

De Rerum Natura

Posted on 14/06/2018 by Neil English

Hubble deep Field Image. Credit: Wiki Commons.

However, the Most High does not dwell in temples made with hands, as the prophet says:

‘Heaven is My throne,
And earth is My footstool.
What house will you build for Me? says the Lord,
Or what is the place of My rest?
Has My hand not made all these things?’

Acts 7:48-50

A new paper by a team of Oxford University scientists, submitted to the Royal Society, London:

Dissolving the Fermi Paradox

Anders Sandberg, Eric Drexler, Toby Ord

(Submitted on 6 Jun 2018)

The Fermi paradox is the conflict between an expectation of a high {\em ex ante} probability of intelligent life elsewhere in the universe and the apparently lifeless universe we in fact observe. The expectation that the universe should be teeming with intelligent life is linked to models like the Drake equation, which suggest that even if the probability of intelligent life developing at a given site is small, the sheer multitude of possible sites should nonetheless yield a large number of potentially observable civilizations. We show that this conflict arises from the use of Drake-like equations, which implicitly assume certainty regarding highly uncertain parameters. We examine these parameters, incorporating models of chemical and genetic transitions on paths to the origin of life, and show that extant scientific knowledge corresponds to uncertainties that span multiple orders of magnitude. This makes a stark difference. When the model is recast to represent realistic distributions of uncertainty, we find a substantial {\em ex ante} probability of there being no other intelligent life in our observable universe, and thus that there should be little surprise when we fail to detect any signs of it. This result dissolves the Fermi paradox, and in doing so removes any need to invoke speculative mechanisms by which civilizations would inevitably fail to have observable effects upon the universe.

Full Paper here

De Fideli.

Paradigm Shifts.

Posted on 08/06/2018 by Neil English

The Romans 1 mindset: Conceding design but denying the Creator; the sorry state of modern origins science.

Blessed is he whose help is the God of Jacob,
whose hope is in the Lord his God,
who made heaven and earth, the sea, and all that is in them,
who keeps faith forever;

Psalm 146:5-6

The winds of change are sweeping through the corridors of biological science. With many more scientists now willing to concede that living things could not have originated without an intelligent agency and did not evolve in a naturalistic sense, some are beginning to revisit an ancient idea; that the seeds of life came here from the stars. We know this today as panspermia.

Panspermia is not a new idea. It appears to have been dreamt up in almost every culture, from ancient civilisations through to the modern era. Like evolution, panspermia is of an entirely pagan origination. The Pre-Socratic Greek philosopher Anaxagoras of Clazomenae (500−428 BC) was one of the earliest documented thinkers who entertained the notion that the ‘seeds’ (in Greek, spermata) of life travel throughout the cosmos. It took on a more scientific formulation with the thoughts of the Swedish physical chemist, Svante Arrhenius, in the early years of the 20^th century and was re−visited in more recent times by a collaboration between the British cosmologist, Sir Fred Hoyle, and the Indian mathematician, Chandra Wickramasinghe, who curiously elaborated on his ideas to include “the possibility of high intelligence in the Universe and of many increasing levels of intelligence converging toward a God as an ideal limit.”

Perhaps the boldest efforts to bring scientific credibility to directed panspermia was made by prebiotic chemist, Leslie Orgel and the English physicist, Sir Francis Crick, in an interesting paper appearing in 1973. According to origin of life researcher, Robert Shapiro, Crick became interested in directed panspermia as a tongue in cheek response to the sheer implausibility of life emerging naturally on Earth. Since then however, the possibility of finding a naturalistic origin for life has become much more remote.

As Drs Hugh Ross and Fazale Rana clearly explain in their excellent book, Origins of Life; Evolutionary and Biblical Models Face Off, outside of living organisms and their decay products, scientists find no ribose, lysine, arginine, or tryptophan —molecules critical for assembling proteins, RNA, and DNA—either on Earth or anywhere else in the Universe. What is more, no conceivable naturalistic scenario is able to generate the large, stable ensembles of homochiral (D)ribose and homochiral (L)amino acids that all naturalistic origin-of-life models require, affirming why no such natural sources have ever been found. Many of life’s critical building block molecules cannot last outside of organismal space and their decay products for more than just a few days, hours, or minutes (for example, RNA rapidly degrades as any biochemist will tell you). Furthermore, early Earth’s abundance of uranium and thorium (by their radiometric decay) would have split enough of Earth’s surface water into hydrogen and oxygen to shut down the chemical pathways to a naturalistic origin of life. As world renowned synthetic organic chemist, James Tour, of Rice University, USA, has poignantly stated:

Life should not exist. This much we know from chemistry. In contrast to the ubiquity of life on earth, the lifelessness of other planets makes far better chemical sense.

The fossil record does not reveal any credible sense of evolutionary progression. Thanks to the first rate sleuthing by Dr. Stephen Meyer, a geophysicist and philosopher of biology (PhD Cambridge University) demonstrated in his best selling book: Darwin’s Doubt, The Explosive Origin of Animal Life, the exceptional speed with which animal body plans emerged with no antecedents, casts severe doubt on any NeoDarwinian scenario being implicated in their emergence. Nor is there any compelling reasons to believe in an evolutionary tree of life, as the work of Dr. Paul Nelson of the Discovery Institute, Seattle, USA, has so clearly shown in this interesting presentation.

In the field of paleoanthropology, the public have been subjected to evolutionary propaganda ad nauseam, and yet despite it all, there is no solid evidence that modern humans evolved from lesser creatures. In recent years, some in the field have changed tactic by attacking human exceptionalism, making dubious claims that creatures such as Neanderthals and Homo Erectus displayed symbolic behaviour, but many of these claims have now been debunked by careful re−analysis of the available data and often by fellow scientists within their own fields.

Great scientific revisions like these scare naturalistic scientists half to death; life cannot emerge naturally, nor has it evolved in a Darwinian sense. Unwilling to accept that a deity was responsible for the origin and diversification of life over 4 billion years, they are now showing signs of ducking these issues and as a consequence, are re entertaining the only possible alternative: directed panspermia by a more highly evolved intelligence (ETI) which emerged elsewhere in the Universe.

But how credible is this scenario? Well, the first question that must be answered is where did that extraterrestrial intelligence come from? Well, it could not have arisen naturalistically for the reasons cited earlier. And the chances of finding a truly habitable planet with all the characteristics Earth possesses even in a cosmos with 10 billion trillion planets is unimaginably remote; just one chance in 10¹⁷². Could living things survive in deep space, perhaps by being protected inside a case of ice or refractory mineral? Over relatively short distances and small timescales, it is conceivable for life to hitch a ride to another planet. Take the case of Mars and the Earth. Over the aeons, both the Earth and Mars have been pummelled by meteoric debris arising from other locations within the solar system. We have identified Mars rocks on Earth and Mars also will have been peppered with terrestrial material. In this way it is scientifically possible that primitive life derived from the Earth might have taken hold on Mars and might even have survived to this day deep underground. But that’s not what directed panspermia is really about though (the ‘pan’ part of panspermia implies a truly universal mechanism) and it would be scientifically naive to jump to the conclusion that any such life had originated on that body.

The chances of life surviving over longer timescales in outer space is also pessimistically low. Free living microbes would be destroyed by deadly X Ray, UV and gamma radiation permeating both planetary and interstellar space. In 2001, Gerda Horneck et al revealed the results of an experiment conducted on board the Russian FOTON satellite, which showed that the highly radiation resistant Bacillus subtilis were all wiped out in just 15 days! Spores of microbial cells hiding inside a dust grain from one solar system to another will likely be propelled by radiation pressure. The irony is that in order for such a dust grain to be propelled by radiation pressure it would require a source of very high irradiance, and since these sources will feature broadband radiation, e.g. X rays and other highly damagaing electromagnetic radiation, it would destroy any such spores in a relatively short time.

What are the chances of a rock derived from another planetary system being delivered to the Earth? An interesting question, no doubt, but it has been calculated. Jay Melosh, a planetary scientist based at the Lunar and Planetary Laboratory in Arizona showed in 2001 that the expected frequency would be of the order of 10^−16 per year. Simply put, there is one chance in a million of just one interstellar rock being captured by the Earth over the entire history of the solar system!

The notion that an advanced spacefaring ETI seeded life on Earth is gaining momentum in recent days. Conceding that the genetic information simply couldn’t have been derived from any known Darwinian mechanism to create new biological diversity, serious scientists are now entertaining directed panspermia by advanced ETI. But in order to do that they would have to surmount a number of problems. In the first instance, they would have to transport the relevent biological material over interstellar distances. That would mean avoiding all sorts of hazards including novae, supernovae, sterilising radiation from giant stars and flares from dwarf stars, not to mention avoiding radiation from galactic spiral arms and the galactic bulge. But there is also the problem of speed. There are very good physical reasons that the maximum velocity such spacefaring ETIs could move through space at is just a few per cent of the speed of light in order to mitigate against the catastrophic effects of a collision with space debris. Even the impact of a dust−sized grain with a spacecraft travelling at that speed would likely end in disaster. And because these speed limits greatly increase travel time, all of the above problems become multiplicative.

Believing Impossible Things

We live in an age of mass deception; there is so much misinformation out there that almost anything goes. It’s difficult to see the woods from the trees, but if you conduct your research diligently and thoroughly you will arrive at a knowledge of the truth. As a conservative Christian, I am guided by the light and truth of the Bible. The secular world wants you to belief that you came from primordial slime and that you somehow evolved through various blob stages and then into a primitive animal, and from there into a higher animal form and so on and so forth. Life has no purpose and no ultimate meaning. Humans are just rational animals, distinguished only in degree from other animals. Morals are relative. The cosmos is teeming over with lifeforms and one species has no greater intrinsic value than any other. Evolution is its driving force.

The Bible, on the other hand, teaches us that God created all life on Earth as an expression of His glory. It teaches us that “we are fearfully and wonderfully made” (Psalm 139:14), as the best available modern science continues to affirm. The origin of human exceptionalism is grounded in the first book of Moses, called Genesis, where it declares that God made Mankind in His own image and likeness (Genesis 1:26). God created humanity from the dirt of the ground of the Earth but says nothing about the stuff from the stars. Intriguingly, the Bible gives very scant attention to the heavens. And lo, when we look to the stars, we do not see that grand evolutionary procession of endless beings, with endless forms. The cosmos is silent, hostile to life where ever we look.

The Bible warns us about deceptions of all kinds but it also instructs us to “test everything” and to “hold fast what is good” (1 Thessalonians 5:21). It encourages us to seek the truth for the same will set you free (John 8:32). Given the grand scientific deception that evolutionary ideology cultivates, just how free are you?

Which world view paints paints a more accurate description of reality: the one promulgated by methodological naturalism or that which is presented in the Biblical narratives? I would suggest to you that it is the latter that presents the truth. And as the days go by, and as we learn more and more about this wondrous Universe in which we find ourselves, that truth grows ever stronger. That’s why I urge others not to abandon the faith held by our forebears. The Bible has much to say on these issues. Indeed, it anticipated them:

Now the Spirit expressly says that in later times some will depart from the faith by devoting themselves to deceitful spirits and teachings of demons.

1 Timothy 4:1-2

So don’t be deceived. Forget panspermia in all its delusional flavours. Embrace the truth gladly and don’t be sidetracked by every story that tickles your ears. For that is the worthless faith of a Biblical ‘fool’.

Further Reading/Viewing

Further theological discussions on ETI and extraterrestrial Life by Dr. John Barnett:

What does the Bible say about Aliens and Extraterrestrial Life?

Ross, H. & Rana, F., Origins of Life; Biblical and Evolutionary Models Face Off, RTB Press, 2014.

Updates on the various chapters from this book available here.

Ross, H. Improbable Planet, How Earth Became Humanity’s Home, Baker Books, 2017.

Bergman, J., Panspermia: The Theory that Life came from Outer Space.

Rana, F., Creating Life in The Lab: How New Discoveries in Synthetic Biology Make a Case for the Creator, Baker Books, 2011.

Meyer, C., Darwin’s Doubt: The Explosive Origin of Animal Life and the Case for Intelligent Design, Bravo Ltd. 2014.

English, N., The War on Truth: Trouble with Astronomy Journalism.

Tour, J, Animadversions of a Synthetic Organic Chemist

Tour J., An Open letter to my Colleagues

Tour, J. Origins of Life, An Inside Story.

Some resources challenging the false doctrine of theistic evolution (especially recommended for Roman Catholics, Anglicans etc):

Moreland, J.P., Grudem, W., Shaw, C, & Meyer, S.. (eds.), Theistic Evolution: A Scientific, Philosophical, and Theological Critique, Crossway Books, 2017.

Chaberek, M.(Fr.),Catholicism and Evolution, Angelico Press, 2015.

Chaberek, M.( Fr.) Aquinas and Evolution, The Chartwell Press, 2017.

Allfree, M., & Davies, M, The Deception of Theistic Evolution, lulu.com, 2017.

Neil English is a keen stargazer and loves debunking deceptions. His latest book; Tales from the Golden Age will look at the life and work of hundreds of amateur and professional astronomers across four centuries of history. Available in late 2018.

De Fideli.

The “Foot” ‘Scope Project: Part II

Posted on 04/06/2018 by Neil English

Foot sized powerhouse; the author’s 12″ f/5 Newtonian.

April 13 2018

In a previous communication, I described my acquisition of a Revelation 12″ f/5 Dobsonian telescope, which delivered fine images of selected double stars and which was used to establish the Taylor hypothesis, namely, that if the seeing conditions are fair to average or better, sub–arc second pairs can be readily observed at appropriately high magnifications using the generous aperture of this telescope.

After conducting this body of work, I have had little time to enjoy the considerable benefits of observing with a big Newtonian system such as this, but in this blog I hope to report still more observations with the same telescope and improve its optical and thermal performance in the field.

During the course of that previous communication, I described the optics in this telescope as being unreasonably good. Indeed, they far exceeded my expectations given the very modest cost of the telescope! I also described some modifications I made to the instrument, including the re–coating of the secondary mirror (just 70mm semi major diameter giving a 23 per cent central obstruction) with super–high (97 per cent) reflectivity coatings as well as the procuring of Bob’s Knob’s to assist precise collimation in the field, but I postponed some other aspects of this project. In particular, I wished to also have the coatings on the large primary mirror similarly upgraded in order that it would increase light throughput to the eye as well as improving the overall contrast of the images so rendered.

Today, I endeavoured to resume work on the telescope and that meant removing the primary mirror from its cell in order that I could despatch it to the mirror coaters located south of the border in England. The mirrors for this telescope were sourced from GSO and seem to have been more or less consistently good, as judged by other experienced amateurs who had taken the time to assess one or more units of the same product. One such assessment is documented here and I would heartily agree with the conclusions of Mr. Stoitsis.

After removing the mirror cell from the rear of the optical tube, I was able to accurately measure its thickness, as well as assess the design of the accompanying cell. The thickness of the mirror was measured to be 36mm (so 1.5 inches), yielding a mirror thickness to aperture ratio of 1:8. This result is consistent with this author’s finding in respect of the ability of the telescope to acclimate adequately to ambient outdoor temperatures, allowing him to make those important observations with regard to resolving sub–arc second pairs.

The 30cm aperture GSO primary has a thickness of 36mm (1.5 inches).

The mirror cell is housed in an open cell. It appears to be well designed and incorporates a 9–point floatation system; just about perfect for a mirror with these dimensions.

The 9–point floatation system of the 30cm aperture GSO primary mirror cell.

The mirror was then carefully packed away for safe passage to the mirror coaters.

Packaging up the primary for re–coating.

I hope to despatch the mirror early next week, so hopefully I will have it back in a few weeks; just in time to explore the deep sky glories of spring!

April 14 2018

Time: 23:20UT

Almost forgot to tell you: several weeks after exchanging resources for the foot ‘scope, I received an envelope in the post. Curiously, I prized it open, and there it was! A small, battery powered fan; the same one that originally came with the telescope! As I explained in the opening blog, I wasn’t too bothered about not having it, nor did I really need it. But it was a warm gesture from the original owner of the telescope to send it on; something I appreciated!

The little fan.

Time: 4:20 pm

As described in previous blogs, I also wish to line the inside of the 1450mm long tube with cork and overlay this with flocking material. Materials were ordered yesterday and should keep me busy until the primary returns home.

April 21 2018

Time: 5:45pm

Lining the 12 inch optical tube assembly with cork.

With a decent spell of settled weather now upon us, I spent the afternoon lining the inside of the optical tube with a thin layer of cork. The product I chose has an adhesive layer on the underside of the cork substrate and adheres to the rolled aluminium tube fairly easily. The cork itself is very delicate though, and so some care must be taken not to tear it while preparing the strips. 3 full 100 x 45 cm rolls were used up today, but I needed to order up a couple of extra rolls to complete the job. These arrive on Monday so I can complete the task then. The flocking material has already arrived so that will be overlaid on the cork. This afternoon, I only flocked the inside of the focuser draw tube.

The mirror arrived safely at the coaters and on the invoice they noted its diameter to be 303mm. Hoping to have it back in a week or so.

Date: April 24 2018

Time: 3:10pm

The tube now fully insulated and flocked.

Well, I finally managed to complete the cork lining as well as covering it over with flocking material. Since the rolls are the same size ( i.e. 45 x 100cm), I can report that it will take 4 complete rolls of each material to insulate and flock the optical tube assembly of the 30.3cm F/5 Newtonian. I’m pleased with the result. All I need do now is wait for the arrival of the primary mirror and I’m back in business.

Date: May 8 2018

Well, the primary arrived back safely from the coaters this morning. I was busy with a few other things so only did a quick check to see that all was well. It was exceptionally well packed for transit. Later on, I gave it a good look over and can say that the firm did another excellent job applying the high reflectivity coating to the 30.3cm mirror, and they centre spotted it, as requested.

The recoated 12 inch primary mirror arrives back home in perfect nick.

Side view.

It was then carefully placed back inside its cell, making extra sure that the clips holding it in place were not overly tightened to avoid pinching of the optics.

Mirror now back in its cell for remounting onto the optical tube.

After putting the mirror back inside the tube, I left it outside to cool in the bright evening sunshine.

The innards of the foot ‘scope.

Following a few hours of rain, it cleared up in the late afternoon and stayed that way well into the evening. So, all I need to do is align the optical train before sunset and I can take it for a spin under the stars.

Awaiting darkness in a race against time.

Yeehaw!

Date: May 9 2018

Time: 00:00UT

What a glorious night! Telescope performed flawlessly!

Boys oh Boys!

Will tell you about it later today.

Starting at about 11:30pm local time, as the twilight had all but abated, the fully acclimated and carefully collimated telescope rendered excellent star tests on a few third magnitude stars, with a very high degree of symmetry in the intra- and extra-focal images at 250x. I could however detect a trace of under-correction, as I reported before, but it was not enough to bother the image in any significant way. In focus, the same stellar targets rendered hard, round Airy disks with no astigmatism or coma at the centre of the field at powers up to 450x (the highest tested this evening). No evidence of pinched optics was manifest.

My first proper target was Izar(Epsilon Bootis) now sitauted high up the southeast. At 250x, the image was remarkable! Both the primary and the secondary were beautifully resolved and intensely bright! Bright targets like this would actually benefit from filtering in this large telescope with a neutral density filter or polariser. As the sky darkened further, I turned the telescope on two stellar targets with very faint companions in comparison to their primaries. Keeping the magnification at 250x, Polaris B stood out wonderfully well; far more ‘in your face’ than the images garnered by even the 8 inch f/6 Newtonian. Even more striking was the very faint and close-in companion to Alula Borealis. The ruddy primary here shines at magnitude +3.5, and the secondary, a feeble +10.1. The 12 inch cleanly resolved the pair separated by about 7.4″ of dark sky, with the companion very obvious and much more easily seen than with any of my smaller telescopes. Where even the 8 inch requires some degree of concentration to pick off the secondary, the 12 inch made it very easy to see at a glance. Indeed, I can’t recall seeing it so well and so easily!

As the sky became maximally dark between midnight and 1 am local time, I turned my attention to a variety of deep sky objects to assess both the light gathering and defining power of the 12″ f/5. And here again, I was not disappointed!

I first turned the telescope on M 51 in Canes Venatici, now very well placed high overhead. Even with the 32mm Plossl I used to centre the galaxy in the field, it was strikingly bright and obvious in the expansive, low power portal. Inserting my 7.5mm Park Gold ocular delivering 200x, I was able to discern far more of the spiral structural details in the galaxy’s spiral arms of this amazing target. Indeed, it was in a completely different league to the views I have recently been enjoying with my 8″ f/6 Newtonian. A very enjoyable experience!

Next, I moved into Hercules, which by this time was well placed high in the eastern sky. Excitedly, I turned the 12″ on its deep sky jewel; Messier 13, the great globular cluster some 23,000 light years away. The instrument served up an amazing image at 200x( 7.5mm Parks Gold), but it was even better at 250x (6mm Baader ortho). The storm of stars resolved in this large aperture telescope was simpy mesmerising and again in a completely different league to that rendered in any of my smaller instruments. For kicks, I cranked up the power to 450x (Parks Gold 7.5mm with a 2.25x Baader shorty Barlow), refocused and sat back to enjoy a field of view littered with innumerable faint, round stars, all finely resolved right down to the core. Lesser instruments just run out of light at these very high powers but not so with the 12″!

Not too far away and significantly higher up in the sky was Messier 92, and once the telescope was centred on it, it produced a wonderfully sharp and well resolved globular cluster, with many hundreds of individual stars clearly seen at 250x (Baader 6mm ortho). As before, while the view in my 8″ f/6 was rewarding, the 12 inch takes you to a whole new level of visual experience!

My final targets were located in Lyra, which I visted shortly before 1am local time. First I turned the telescope on the famous Double Double (Epsilon 1 & 2 Lyrae). At 250x, all four components were beautifully resolved and intensely bright, more like distant coach lamps etched onto the sky than anything else. Slightly lower in altitude was M57, the famous Ring Nebula. At 250x, the image of this planetary nebula, more like a luminous smoke ring, was big and bright and easy to study. Generous amounts of structure were delineated at 450x along its southern border, with many gradations of brightness, mottling etc observed in the brighter outer annulus. Central star not seen (of course!) but many more stars observed in its immediate hinterland than that presented in the 8 inch instrument.

Conclusions: The telescope delivered great images, fully in keeping with its large, high quality optics. I am adequately convinced that the 12″ gains that extra (approximately) one magnitude over the 8 inch telescope, allowing many deep sky objects and faint stellar companions to be more easily studied. Throughout last night’s vigil, the stellar images at very powers remained tight and calm, suggesting that the insulating cork lining was doing its job (no fan used). All images were presented with very good contrast and with little in the way of stray light drowning out the faintest details. If anything, the experience in the field induced strong desires for even more aperture. But it is reassuring to realise that in order to gain yet another magnitude in light grasp, I’d have to move up to an 18 inch!

I am over the Moon with the performance of this telescope, which was purchased for just a few hundred pounds. And even with the additional costs of the modifications, the overall financial outlay came in at about half the price of my most expensive telescope; a diminutive but very fine 5″ f/12 refractor. Heck, that telescope would make a good finder on the 12 inch behemoth lol.

Date: May 10 2018

Time: 20:15 UT

The foot ‘scope passively cooling.

The forecast looks good again this evening and so I can spend more time with the foot ‘scope. I leave it set up in my back garden with the optics capped and let it cool naturally to ambient temperature for a couple of hours before commencing observations. That way I can return to my writing committments and/or other things. Although one can have the instrument set up permanently in a cool outhouse, I want the coatings I invested in to last as long as possible. Water vapour and its condensations are the enemies of all optical coatings, so that’s why I store all of my Newtonians indoors when not in active use. My Newtonians are all long term committments; parts of my family, as it were. And like everything else that is valuable in life, it pays to give your instruments a bit of TLC if they are to deliver top perfomance time and time again.

Date: May 11 2018

Time: 23:00 to 00:30 UT

I enjoyed another hour or so of good dark skies last night, visiting a whole suite of double stars in Coma Berenices and Bootes, which were well placed near the meridian at this time. Conditions were a little hazier this evening though, reducing transparency.

There are two lovely doubles in Coma worth visiting; 24 Com, which consists of a gorgeous colour contrast double, the primary shines with a ruddy complexion at magnitude 5 while the ‘secondary’ has a gorgeous blue white hue some 1.3 magnitudes fainter. The system is orientated roughly east to west and very nicely framed at 200x. I say ‘secondary’ as it is unknown whether this is a true binary system and at this time, the consensus appears that they are unrelated. The second system visited was 35 Coma, with the telescope easily resolving this tight duo of yellow and yellow white components with a striking 9th magnitude outlier. I believe this system is a little over 1 arc second at the present time but is slowly converging over the next few decades. A power of 450x was found to be optimal to splice this puppy, the components of which are 5.1 and 7.1. The orbital period of this system is about three and a half centuries.

Then into Bootes; Iota, Epsilon,Kappa, Mu, Pi and Xi were beautifully rendered at 200x to 250x. With the generous aperture of this telescope, the stellar members of these systems were very brilliant and colour faithful. Seeing was not as good last night as on the previous night, but I was extremely impressed at how the instrument maintained high quality images over periods of a few minutes, as each system in turn was studied at leisure.

Yet again, I was very impressed with the optical prowess of this large telescope. It holds collimation well (I checked it at various times and in various orientations throughout the vigil), perhaps a tad better than my other Newtonians. It also appears to be behaving itself thermally, which is a great relief. Again, no active cooling was employed.

As I was packing up my gear, I realised that I had not named this telescope properly. I can’t just call it the ‘foot ‘scope’ forever now can I? But what shall I call it? Not ‘Alexa’ to be sure; far too creepy for my liking. I need to spend more time with the instrument before I decide.

Time: 13:15 UT

A quality focuser.

I am thoroughly enjoying the sturdy dual speed focuser on the 12″ f/5. All my other Newtonians have simple, singe speed focusers but having the ability to very finely adjust the focus position during high power applications is a great bonus. Frankly I’m amazed that the manufacturers were able to offer this feature as standard equipment with the telescope. A super nice touch!

Well, though the morning was quite cloudy, with the rain arrving on schedule this afternoon, the forecast says that it will quickly pass through, leaving the evening clear once again. I would like to return to the realm of the globular clusters; but not in Hercules. There can’t be many dark nights left what with summer twilight knocking on the door.

Time: 23:00UT

The sky has not yet cleared up. Up early tomorrow so need to call it a night anyway.

Date: May 14 2018.

Time: 23:00 UT

The light bucket.

After a cloudy and wet morning, the skies cleared to give a beautiful sunny afternoon. Those conditions gave way to a good clear night, but even at midnight local time, the twilight has noticeably brightened in the last few days, especially towards the north. I set the foot ‘scope out about 10pm local time to fully acclimate prior to resuming observations. Tonight I wish to begin with another celebrated globular cluster, Messier 3, conveniently located almost exactly half way between Arcturus and Cor Caroli.

Time: 00:15UT

Another great night, although the seeing was a bit rough. Nonetheless, some great sights captured in the foot ‘scope. Will tell you about what I got up to later today. Nite nite.

Starting about local midnight, I trained the 12 inch Dob on Messier 3 in Canes Venatici. Centring the object in the low power (47x), approximately 1 degree field of my 32mm SkyWatcher Plossl, I noted a fairly bright field star just west of M3 which provided a means to carefully focus the image. Messier 3 has a very condensed core with quite a few stars being resolved at its periphery. Both my 5.1″ and 8″ Newtonians are well able to resolve the outer parts of this globular cluster but the core remains stubbornly unresolved even at higher powers. Not so with the 12″ instrument, which opened up this globular at powers of 200x and 250x, showing many more stars resolved to its core. The instrument works well with simple, short focal length eyepieces. Indeed, my 4mm Revelation Plossl, which delivers a power of 375x, produced a truly wonderful view, where its constituent stars filled the 0.14 degree field of view. Tracking the instrument was never a problem owing to the smooth azimuth and altitude bearings on the Lazy Susan mount, which enables me to nudge the telescope along as the object drifts through the field from east to west.

M 3 is noticeably smaller than M 13. But it is also located some 10,000 light years further away from the solar system than the latter, explaining its smaller angular size at equivalent magnifications.

This telescope is worth every penny spent on it just for the quality of the views of globular clusters alone. The foot ‘scope is a veritable “glob buster.”

I recorded 4 bright telescopic meteors during my 75 minute vigil.

Keen to get a look at some other showpieces before the worst of the twilight returns, I turned the telescope on the bright galaxy pair, Messier 81 & 82 in Ursa Major, and my trusty 32mm Plossl framed both galaxies in the same field of view. Even at this low power, the generous light gathering power and resolution of the telescope displayed these galaxies extraordinarily well, with prominent mottling in M82 evident at a glance along its major axis. Cranking up the power to 200x using my 7.5mm Parks Gold, clear spiral structure in M81 could be made out without much effort. Again, the level of detail seen in these galaxies is a very significant increase over my next most powerful telescope; the 8″ f/6 Newtonian.

Time: 21:15 UT

Another clear night beckons, so more tests can be made on the foot ‘scope.

Date: May 15 2018

Time: 00:20 UT

Tonight I enjoyed a stellar extravaganza, cruising at 200x through a wilderness of light and colour. More info later today.

Last night’s spell with the telescope took me to a variety of colour contrast double stars. First came 30 and 31 Cygni, arguably one of the most comely binocular doubles in the entire sky, the brilliancy of the stars and their colours; orange and turquoise were beautifully framed in the 0.25 degree field of my 7.5mm Parks Gold eyepiece delivering 200x (a rather pedestrian magnification for this large telescope). While smaller ‘scopes certainly present this vista well, the view is truly transformational in this large aperture telescope owing to its superior light grasp and defining power. I then moved south to Beta Cygni (Albireo) and enjoyed a wonderful view of the marmalade orange primary and blue –green secondary at the same power. It was just a joy to see them so faithfully rendered in their true colours and shining so intensely in the telescope.

Following this, I ventured into the large and sprawling constellation of Hercules, starting with Rasalgethi(Alpha Herculis) with its red giant primary and bluish companion perfectly framed in the eyepiece. Then I threw caution to the wind and moved higher up the sky visting each star brighter than 5th magnitude within the constellation, examining their hinterland in the 200x portal. As I moved from star to star using the 8 x 50mm finder, I was amazed at the sheer light gathering power of this telescope and the number of extremely faint stellar ‘companions’ which attended many of the brighter stars. Where my smaller telescopes only revealed the brighter members or none at all, the 12″ f/5 pulled in many more! I was reminded of the work of the English amateur astronomer, the Reverend T.H.E.C Espin of Tow Law, Northumbria, who used a 17.25 inch equatorially mounted Calver reflector at the turn of the 19th century to discover a sizeable tally of these faint and wide companions strewn all across the northern sky. It seems that good reflecting telescopes are ideally suited for such work. Indeed, they can hardly be beaten in these pursuits!

With every increase in magnitude, there is a corresponding increase in stellar number, but there is no fixed power law that might enable us to compute how many more stars there might be as the magnitude is increased. The distinguished 19th century German astronomer, F. W. Argelander, estimated that each magnitude exhibits a rise of about 300 per cent. Indeed, in data presented on page 294 of W.F. Denning’s masterful tome, Telescopic Work for Starlight Evenings (1891), he provides these figures, collated from a survey between 2 degrees south of the equator all the way to the north pole:

1st: 20

2nd: 65

3rd: 190

4th: 425

5th: 1100

6th: 3200

7th: 13,000

Having spent some time traversing the stars of Hercules, I can definitely see that Denning was on the right track. Indeed, I would say that the 12 inch instrument does yield an approximately three fold (maybe more) increase in star numbers over my optically excellent 8 inch f/6 Newtonian; and in many cases that is sufficient to change the visual perspective of each telescopic field by a considerable degree. In small telescopes, many star fields can present as rather bland and uninteresting. Patently not so with the 12″ f/5!

Although the sky is clearing up as I speak, I have decided to take a break tonight as I’m knackered and need to recharge the ‘batteries’. More to come soon.

Date: May 16 2018

Time: 18:00UT

I love the low tech approach of the Dobsonian. No electronics to fiddle with, no star alignments to perform. Just mount it on its lazy suzan and you’re off to the races. But this simple approach doesn’t suit everyone. In particular, many prefer driven mounts that keep objects centred in the field while making observations. If that’s your forte then there’s a solution; enter the driven Dob mount. Many such equatorial platforms are available for purchase today and they vary quite a bit in price, but these days you don’t have to spend a fortune acquiring one. Have a look at this one, for example. All you need to do is adjust the inclination of the platform to coincide with your latitude(in my case it’s 56 degrees North), power it up and you can enjoy an hour of active tracking before you have to reset it. If you do decide on one, you need to ensure it can be adjusted to your latitude angle. That’s why a variety of them can be purchased to suit your precise location, either south or north of the equator.

The good Lord has granted us a spell of settled weather here and tonight looks very good to go. Where will my foot ‘scope carry me off to this evening?

Date: May 17 2018

Time: 00:30UT

The Wide field experience.

Tonight I stuck mainly to low power, wide–field viewing. When coupled to a good 2 inch wide–angle eyepiece, the foot ‘scope serves up some spectacular views! More later.

Time: 20:00UT

Last night the foot ‘scope did experience some thermal issues as it struggled to follow the rather large temperature differential between daytime highs and night time lows. This time of year, we tend to experience larger temperature swings than in other months where it is not especially unusual for the diurnal temperature variation to exceed 15C (as opposed to about 5 or 6 degrees which is normal). As a result, high magnification images of stars were quite swollen and, in the absence of any breeze, I considered using the battery–powered fan. In the end, I changed strategy and decided to explore the wide field sky around Lyra and Cygnus.

Beast of an eyepiece: the Explore Scientific Maxvision 40mm wide angle ocular.

The telescope came with two eyepieces from the former owner; a Revelation 30mm 70 degree Superview 2 inch ocular, as well as a 9mm Revelation Plossl. The former unit was quickly found to be adequate on axis but rather poor off axis, with coma, distortion and astigmatism being in evidence. To enjoy a much more immersive view, one needs to invest in a higher quality wide angle ocular. The 32mm Plossl gives a significantly smaller true field but off axis aberrations are still manifest. To this end, I removed the 1.25″ adapter on the focuser and reached for my 40mm Explore Scientific Maxvision 68 degree eyepiece, which has been used extensively over the last few years with my 8 inch f/6 Newtonian.

While the exit pupil was pushing 8mm on the 12″ f/5, I was delighted with how well it performed. Yes, there was some minor light loss but otherwise it served up excellent, bright and sharp images of star fields out to about 90 per cent of the way to the field stop. And even then, the distortions were more than tolerable. The Maxvision eyepieces are clones of the longer established Meade Super Wide Angle(SWA) and Tele Vue Panoptic oculars, but are offered at significantly lower prices.

To best match the faster f/5 system of the foot ‘scope with my 49–year–old eyes, I ordered up the 34mm unit, which will deliver an excellent 1.5 degree true field, a magnification of 44x and sub–7mm exit pupil. This will be an excellent eyepiece for sweeping the heavens for comets, faint nebulae and open clusters on the precipice of visibility. A large, high–quality telescope like this deserves a good, wide angle eyepiece. The Maxvision range offer this quality at very attractive price points (£114 plus postage). I’m hoping to receive the unit by the middle or end of next week. Of course, there are other options for money conscious amateurs; the second hand market is likely to have something suitable come up from time to time and with patience and discernment, good deals can be had.

This evening looks good to go again, but I would like to take a break from the foot ‘scope for a few days and feed some starlight to my smaller instruments. More soon.

Date: May 18 2018

Moon watching.

Time: 21:30UT

Last night I enjoyed a wonderful evening of double star observing with my 130mm f/5 Newtonian.The sky was very tranquil, allowing almost textbook perfect images to be generated on a variety of systems. The good weather remains with us again today and this evening I noticed a beautiful crescent Moon hanging in the western sky. I just couldn’t resist the chance to observe it in the 12″ f/5. My 32mm SkyWatcher Plossl delivered a jaw dropping view of the crescent at 47x in a one degree field and the wondrous earthshine enveloping its darkside. Reaching for my 7.5mm Parks Gold delivering 200x, I was delighted with the razor sharp views of the lunar regolith, especially considering its fairly low altitude at the time of observation. Though not a lunar observer per se, I look forward to observing this magnificent world with the foot ‘scope as it rises higher in the sky in the coming days.

Date: May 21 2018

The new 34mm 68 degree Maxvision eyepiece arrives tomorrow, so not as long a wait as I anticipated.

Date: May 22 2018

Time: 21:30UT

The foot ‘scope fighting the Spring haar.

I set the foot ‘scope out late this evening so that I could get a quick look at a fairly well placed first quarter Moon, with the express intention of testing the high magnification images garnered by the telescope. In the end, it proved an exercise in frustration more than anything else, as the haar (low altitude cloud and mist) came rolling in off the North Sea from the east as soon as the Sun’s rays became weakened by its falling altitude in the northwestern sky. I did however manage to get some quick peeks at the lunar surface at powers of 250x (6mm Baader ortho) and at 375x (4mm Revelation Plossl). I can report that both ‘high power’ oculars delivered very sharp and detailed images of the lunar regolith in twilight, demonstrating that these powers can be productively used on extended objects like the Moon and the planets in the foot ‘scope. That said, I’ve used nearly double these powers on sub–arc second double stars in work conducted during the summer and autumn of last year.

Alas, the courier never showed up today with the eyepiece……ho hum.

Maybe tomorrow lol!

Date: May 23 2018.

Time: 12:20 UT

The Explore Scientific 34mm 68 degree Maxvision eyepiece.

Well, the new 34mm eyepiece has finally arrived.

Schmokin’!

It’s a scaled down version of the venerable 40mm.

The 34mm Maxvision ocular(left) in comparison to its 40mm counterpart(right).

What I especially like about this series of wide angle eyepiece is that they provide excellent performance in a no–frills package. It came in a plain box with no colourful logos and no advertising brochures. Compare them to the now discontunued Meade SWA incarnations;

The now discontinued Meade Series 5000 Superwide Angle eyepiece family.

I seem to recall that the Meade 34mm SWA retailed for £249, but were reduced in price for clearance after they were discontinued. Many retailers do not offer the Maxvision series but appear to be selling a hermetically sealed (argon purged) product with a re–designed body for £219.

So, I was able to purchase essentially the same eyepiece for a little over half the price of the latter. That’s what I call a bargain!

You might need to shop around to get your hands on these eyepieces, but I was able to secure this one from Rother Valley Optics.

Of course, I could have gone for some 82 degree wide angle eyepieces which would provide a slightly larger true field (approximately 1.6/7 degrees), but my eyes seem to prefer 68 to 70 degree fields.I appreciate that this is a highly personal choice though.

The Maxvisions seem to be enjoyed by many amateurs. See this thread, for example. Some amateurs prefer to de–cloak them for some reason, perhaps to pare down their weight or to make them look more appealing, but I have never seen the need to do so.

The stubborn haar is still with us and though my skies are currently blue, it will likely roll in off the North Sea later this evening.

No matter, I’ve done good!

Time: 14:05UT

Gaius, the author’s beloved 80mm f/5 ShortTube refractor fitted with the 34mm eyepiece.

I couldn’t wait to see how it performed, so I mustered my 80mm f/5 achromatic telescope and inserted my Televue 2 inch Everbrite diagonal and in went the 34mm Maxvision.

Wow!

The eyepiece delivers a wonderful, wide field at 12x giving a 5.75 degree true field. The field stop is hard and well defined and contrast appears to be excellent. With these eyepieces one can readily adjust the distance of the large eye lens by rotating the upper section to provide the optimal level of viewing comfort.

I’m currently writing a book that is wholly dedicated to the ShortTube 80 achromat and one of those chapters will de devoted to choosing eyepieces for use with it. I hope to perform more critical tests on the night sky in due course.

The 34mm will also serve Octavius, my 8 inch f/6 Newtonian, by delivering a power of 35x in a field just under 2 degrees in extent.

Carrying on the work with the foot ‘scope.

Time: 21:45 UT

Contrary to what I expected, the haar did not roll in in the late evening, and it is still clear just now. I set the foot ‘scope out again at 19:00UT and was able to continue my high magnification testing of the early gibbous Moon. I began observing at about 20:40 UT when the Moon had past the meridian and was located at an estimated altitude of about 37 degrees. This was a good altitude to test the defining power of the 12 inch. On fine days like this, the air can be very tranquil in the minutes immediately after sunset and so I began with 200x (Parks Gold 7.5mm). Eventhough the sky was far from dark at this time, the lunar regolith presented with razor sharpness and very good steadiness. Ditto at 250x. Then I attached my Baader 2.25x Barlow to the 7.5mm Paks ocular which delivered a power of 450x. Carefully focusing, I was delighted to obtain a wonderfully sharp and (still) fairly stable image. Having the facility to use the microfocuser proved very useful. Looking at the ragged crater walls, I could see details which I do not recall observing in my 8 inch at high powers.

This was a most satisfying result! This instrument is indeed capable of very high powers on extended objects like the Moon and a solid indicator that the optics are of high quality, but I am also fortunate enough to live in a place where the seeing will allow a 12 inch to work beyond the remit of my 8 inch telescope.

I’m away out again to conduct some further observatons and to test the 34mm Maxvision ocular. Shall report back later.

Time: 22:45 UT

Well, the haar has come back lol. It was rolling in as I was writing the last section of the blog. But there was a few suckerholes in the sky and I naturally took advantage of them. My first target was Capella now located quite low down in the north northwest. Charging the foot ‘scope with the 34mm Maxvision I can report excellent results. The bright first magnitude star remained pinpoint sharp across the vast majority of the field while wearing my eyeglasses (which correct for the astigmatism in my eyes). Only at the extreme edge of the relatively massive field did the star show signs of field curvature, coma and astigmatism. The same was true of Polaris located at an altitude of 56 degrees above my northern horizon.

Intriguigingly, I also tested the same eyepiece on my 80mm f/5 achromat. The results were broadly the same but I would say that there was slightly less aberration at the extreme edge of the field of view! It had field curvature and astigmatism but not much in the way of coma. Thinking about this for a few moments, I figured that this slightly better result is due to the fact that even at f/5 an achromatic doublet has very little coma inherent in the design. This is a relatively unsung virtue of modern refractor optics.

So a very good result, which left me very satisfied indeed. The eyepiece does exactly what it says on the tin. No hyperbole; just great performance at an excellent price!

Happy camper.

Need to pack up all the toys now and return to barracks.

Date: May 25 2018

Time: 00:05 UT

Just a quick report from tonight. I only fielded Octavius, my 8 inch f/6 Newtonian this evening to test out the 34mm Maxvision ocular. True to form, it delivered fantastic views and just that little bit better correction right at the edge of the field. I’m going to have an absolute ball with this when dark skies return later in the summer!

My main high resolution target was 78 UMa, conveniently located very near Alioth (Epsilon UMa), one of the stars that form the handle of the Ploughshare. My notes inform me that I’ve not revisited this system for close on three years. And it’s got tougher! The separation was about 0.84″ in 2015 but judging by observations conducted tonight using a power of 500x in good seeing conditions (II) at its currently high altitude above the horizon, I would say that the companion is nearer 0.7″. It was spotted roughly east of the primary and pretty much kissing it but I need to make more observations, especially with the foot ‘scope. The primary is magnitude +5.02 and the secondary +7.88.

Further Adventures with a 3″ Achromatic..

Posted on 19/05/2018 by Neil English

An amazing performer; the Orion SpaceProbe 3 reflector.

Dedicated to John Wall (1932–2018).

a chromatic: literally, without colour.

There has never been a better time to begin the hobby of telescopic stargazing. In past generations, owning a good telescope often proved to be an expensive venture, typically involving many months or even years of saving up. Thankfully, such days are well and truly behind us. Today, you can purchase a decent quality telescope for a very light financial outlay. Indeed, I always advise novices not to spend a great deal on their first telescopes, especially if they are unsure whether or not they intend to pursue the hobby in the longterm. In addition, many people will end up being ‘casual’ or ‘occasional’ observers and so splashing out lavish sums of money on an instrument that sees little net use doesn’t make a whole lot of sense.

In this capacity, one of the best novice ‘scopes I have personally come across is the Orion SpaceProbe 3 reflecting telescope (pictured above, fully assembled), which set me back about £70. That money bought me a very good 3 inch (76mm) telescope, together with a decent mount and two good quality eyepieces delivering magnifications of 28x (using the 25mm ocular) and 70x (when the 10mm eyepiece is employed) and an excellent instruction manual written by an experienced astronomer to show you how to set up the telescope properly, as well as guidance on how to keep the optics in tiptop condition.

All good starter ‘scopes need a good instruction manual.

The Orion SpaceProbe 3 is the latest incarnation in a long line of Newtonian reflecting telescopes, so called because its ingeniously simple design was invented by Sir Isaac Newton around 1668. Over the years, the Newtonian telescope has been steadily improved and refined so much so that today it is arguably one of the most popular kinds of astronomical telescope on the market. Generations of skygazers have enjoyed the crisp, bright images served up by these telescopes, allowing them to conduct detailed observations of a wide range of celestial real estate, from the Moon and the the bright planets, to pretty star clusters, nebulae and distant galaxies in the depths of space.

The optical tube displays the basic optical information of the telescope, including its aperture (76mm) and focal length (700mm).

The Space Probe 3 telescope has a focal length of 700mm and we need to know this number in order to calculate the magnification being used with any given eyepiece. Fortunately, it’s a simple calculation; just divide the focal length of the telescope by the focal length of the eyepiece. So the 25mm ocular produces an enlargement of 700/ 25 = 28x and the 10mm eyepiece provides a power of 700/10 = 70x. Although these will give very pleasing views at ‘low’ and ‘medium’ power, one will eventually need to stretch the magnification some more to get the best views of high resolution targets like the Moon and bright planets. Furthermore, by dividing the focal length by the aperture, i.e. 700/76, we obtain a quantity called the focal ratio of 9.2 or f/9.2. The significance of this number will become important as I elaborate on the optical quality of the telescope in due course.

My field testing over the last two months has clearly shown the potential of this little telescope. A good instrument ought to garner sharp images at powers of 50x per inch of aperture. So according to this reasoning, a 3 inch reflector ought to handle 150x. But I can assure the reader that this telescope can handle considerably higher powers and these high powers can prove very useful for certain kinds of astronomical observations. I have used the instrument profitably at powers of 210x or more but one must also bear in mind that as one pushes the magnification to these high values, the images become rather dim owing to the small 3 inch mirror gathering the light.

By far the most economical way to achieve a greater range of magnifications is to invest in one or two Barlow lenses. Typically they will boost the power of any eyepiece by a factor of anywhere from 1.5 to 3 times. You can get a decent Barlow for just a few tens of pounds (it’s always worth watching out for one on the secondhand market too) and when skillfully chosen, can turn two eyepieces into four or even six. For example, a 2x Barlow will enable the two eyepieces supplied to give additional powers of 56x and 140x. For this particular study, I employed 2.25x and 3x Barlows, providing high powers of 158x and 210x, respectively, when coupled to the 10mm eyepiece supplied with the telescope.

The eyepieces and Barlows used with the telescope. From left to right: the 25mm ocular, the 10mm ocular, the 2.25x and 3x Barlow lenses.

One of the most attractive features of the telescope and its mount is its overall weight; just 8.4 pounds (3.8 kilos)! That means that most anyone can move the fully assembled instrument about. The lightweight, but strong aluminium tripod can be collapsed or extended for seated for viewing or by standing. I decided to use the instrument without its accessory tray so as to maximise the stablity of the tripod. In addition, I elected not to attach the slow motion control bar. This is a strategy I have adopted for many years now, as I like to keep the up−down (altitude) and sideways (azimuth) motions to be as free as possible whilst in ue. With many hours of practice, I have learned to nudge the telescope along smoothly and with minimal vibrations, even at high power. I accept that this is essentially a learned skill and that others may not be happy with it. Only time spent at the telescope can ultimately sway you in one direction or another, and I would encourage as much experimentation as possible in this regard.

To get the very best images out of this telescope, the user must ensure that the optics are accurately aligned. The user manual with the supplied collimation cap and Philips screwdriver will enable you to accurately execute such a task. Experience shows that once this is done, the telescope retains very accurate optical alignment, even after being moved from indoors to the outside many dozens of times. This fine tuning of the optical train will make a noticeable difference to the high power views especially.

By and large, telescopes are not status symbols. How they look counts for practically nothing in the scheme of things. That said, this telescope is well made and is handsomely finished. It ‘looks’ like a ‘proper’ telescope and performs like a ‘proper’ telescope. The rolled aluminium tube is finished in an attractive British ‘racing green’. Some readers concerned more with appearances than anything else (an ugly reality for some, unfortunately) will no doubt fuss over whether or not it ‘looks the part’ and may falsely ascribe importance to what ‘others’ might think. This rather sad state of mind can be entirely dispensed with however, when one realises that amateur astronomy is very much a small ‘goldfish bowl’. The vast majority of folk I have shared my telescopic experiences with know next to nothing about telescopes and can’t discern anything from its appearance. Indeed, you’re as likely to find a telescope like this in a New York penthouse balcony than in a tenement of a working class community. Telescopes are just not like cars! So, if you’re concerned about something as trivial as ‘looks,’ you’re probably in the wrong hobby!

To get an idea of how good the optics are in these telescopes, it pays to take the instrument out during daylight hours. I like to observe nature with as many of my telescopes as possible and usually select a good spot in my garden, out of direct sunlight, and give the instrument a few minutes to settle down in its new environment. To work at its best, any telescope must be allowed to equilibrate with its ambient environment. Failure to do so will provide less than optimal (read disappointing) results, especially when the telescope is ‘pushed’ to high magnifications. I recommend starting with the lowest power eyepiece; this will be the 25mm Explorer II ocular supplied with the telescope delivering 28x. I usually select a distant tree top a few hundred yards distant or some such which I can zoom in on. Care must be taken to avoid observing targets over possible heat sources, such as rooftops and the like.

Once a suitable target is chosen, crank up the magnification gradually, carefully touching up the position of best focus by moving the drawtube housing the eyepiece slowly back and forth until the sharpest possible images are produced.

Good focusing is an essentail skill, especially when attempting to ‘push’ the magnification of the telescope.

By engaging in such an activity, I have discovered that the telesope can take high powers in its stride. The images remain crisp and sharp right up to 210x and beyond, especially on bright sunny days. This comes at the expense of image dimming though; higher powers yield progressively dimmer images. This image quality is no doubt facilitated by the high focal ratio of the telescope (f/9.2 in this case). When the focal length is long in comparison with the aperture of the ‘scope, geometrical aberrations are minimised; less field curvature, coma, distortion, spherical aberration, astigmatism etc. This alows for the use of simpler and less expensive eyepieces so that using the telescope will not create a ‘black hole’ with your resources.

Oh deary me!

In this way, you will discover that this telescope is a very sharp shooter that will embarrass owners of much more expensive telescopes of comparable aperture. The images you will enjoy are true and honest; a simple consequence of the laws of optics and good execution. Here’s an image taken my the US−based amateur, Joe Roberts, who took the time to image the first quarter Moon at prime focus (be sure to click on the image for a good close up) with the same telescope albeit on a sturdy motorised equatorial mount. I hope you will agree that this little telescope is no toy!

More a hindrance than a help: the EZ finder that comes with the telescope.

One of the Achilles’ heels of this telescope package might not be uncovered until one spends a good few hours in the field. Specifically, many decent−sized telescopes come with the equivalent of a ‘rifle sight’ or ‘finder’ telescope, which usually attaches to a bracket found on the top of the main telescope, adjacent to the focuser draw tube. Once aligned with the main telescope, it serves as a very useful tool to find and centre objects quickly. But the ‘finder’ supplied with the Orion SpaceProbe 3 is not a telescopic ‘finder’ as such, but a non−magnifying device (the EZ finder) that projects a small red dot onto a plastic screen which the user is required to co−align with whatever object is to be observed in the telescope. However, a few sessions of active use with the EZ finder will convince most of its inadequacy. For one thing, the EZ finder can only be used with the brightest stars and for those who live in towns and cities, where light pollution may be a concern, using it will prove more an exercise in frustration than anything else.

For this reason, I would strongly recommend the user swap this device out for a regular finder telescope; a small traditional finder ‘scope magnifying perhaps five or six times and having an objective (front lens) of about 30mm. These can be purchased on the used market for very little money. Indeed, if you play your cards right, you may find a sympathetic amateur who will provide you with one for free! Mounting such a finder ‘scope will greatly enhance the enjoyment one can have with the telescope. You’ll be able to focus in on much fainter targets, and learn how to ‘star hop’ from one object to another.

Close up of the finder I mated to the scope; note the matching colour and texture of the finder bracket with the focuser and rim of the optical tube assembly. Schmokin’

Before you can use the finder, it must be aligned with the main telescope. This is easy to do in daylight. Just select a distant target (as far away as posible and at least a few hundred yards in the distance) and centre it the main telescope. Now look through the finder ‘scope and move the cross hairs of the finder so as they coincide as precisely as possible with the image in the main telescope. This is usually done by tigtening or loosening a set of screws in the bracket mounting the finder. Once that’s done, move the telescope to a different target and check to see that the subject you have centred in the main instrument is also centred in the cross hairs of the finder ‘scope. If so, you’re ready to rock ‘n’ roll!

The position in which the observer looks into the telescope has a direct bearing on viewing comfort. And the more comfortable the telescope is to use, the more you will use it. In this capacity, the convenient location of the focuser drawtube makes it easy to observe objects situated at low altitudes but it is while viewing targets high in the sky that the great utility of the Newtonian design shines through. As a former refractor enthusiast, I certainly do not miss the extraordinary degree to which one has to crouch down into very uncomfortable positions near the ground in order to view a high altitude target for any length of time. The simple truth is that Newtonians dispense of much of this hardship. Because I value my back and my posture, observing with the Orion Spaceprobe 3 provides a good way forward.

Every budding telescopist needs a guide book of sorts. It can be hard to know what’s what, observing from a bright, suburban sky, and from a dark site, where the full glory of the heavens is manifested, it’s very easy to get confused. That’s where a simple guide to the night sky is so useful. It will be prove indispensable as your knowledge and observing skills develop. There are many good literary guides available to the modern amateur. I especially like Ian Ridpath and Wil Tirion’s Stars & Planets (Collins 2017). It’s strength lies with its simplicity. You can use the seasonal and monthly maps to find the outline of a constellation you wish to explore and then home in on your selected target(s) for the evening. The lunar maps are very good too. Overall, I have found it an invaluable aid to small telescope forays in the northern hemisphere, but is equally at home under an antipodean sky.

The new edition ( October 2017) of a favourite observing guide.

Finally, though it may seem a bit old fashioned nowadays, I recommend that all observers adopt a culture of regularly recording the sights and sensations one experiences while at the telescope. Notes are an important thread to the past. It’s amazing how much one forgets as the years go by, and it is so reassuring to have the means of consulting earlier work in matters that may prove important at some later time.

OK. With all that said, we’re now ready to begin an adventure together under the stars, exploring something of the extraordinary riches of the heavenly creation. It is fitting to begin this journey with the brightest and most accessible object in the night sky; our glorious Moon.

Oona: a perfect ‘scope for moongazing.

Date: January 31 2018

Time: 22:00 UT

Conditions: Clear, bright sky, very little cloud, bright full Moon.

Temperature: 0C

Tonight is a Super Blue Moon. This means that the Moon is bigger and brighter than average (that’s the ‘super’ bit). It is also the second full Moon in the month (making it’ blue’), the last one occurring on January 2nd last. Inserting the 25mm Explorer II eyepiece and focusing the telescope shows a big bright orb. Indeed it’s almost dazzlingly bright, prompting some observers to reach for a neutral density filter to cut away some of the glare and reduce eye strain. Notice also that the reflected light from the full Moon makes the background sky very bright, drowning out the light of many of its fainter stars.

Did you notice that the image of Moon is both upside down (meaning north is at the bottom and south is at the top) and back to front (meaning east and west are the wrong way round)?

All of this is completely normal with a Newtonian telescope. Indeed, spatial orientation is of little importance in the pursuit of astronomical bodies. You’ll soon get used to it!

Now, looking at the Moon itself with the 25mm eyepiece delivering 28x. Notice how big the entire field is. Indeed, you can easily see that it will fit about three full Moons from one side to the other. Since the full Moon subtends an angular size of about half a degree on the sky, this gives you an idea of how large the field is in the 25mm Explorer eyepiece; about 1.75 degrees. That’s plenty big enough to see the vast majority of deep sky objects, as we shall see on other evenings.

Chances are you’ll have also witnessed two ray craters on the lunar surface. Down near the bottom of the Moon (as you observe it in the northern hemisphere) is Copernicus and the one near the top is called Tycho. Can you see how rays of bright matter seem to stream from these craters? The rays are caused by ejected material gouged out when a large, rocky body collided with the lunar surface in the distant past, ejecting huge quantities of material away from the crater and in all directions (that is, radially). Such ray craters are very old: Tycho is believed to have formed some 100 million years ago, while Copernicus is thought to be 10 times older still (so a billion years or so).

The two prominent ray craters visible in the telescope; seen here in the correctly orientated view.

Because your telescope is a reflector, it shows the true colour of the lunar regolith. Looking closely at its surface will convince you that it has many shades of white and grey, revealing something of its mineral content and age.

Next, remove the 25mm eyepiece and replace it with the 10mm. After centering the Moon and refocusing; you will note that the field of view is considerably smaller and yet it’s still larger than the size of the full Moon. Indeed, this 70x eyepiece serves up a fairly generous field of view of about 0.7 degrees.

It follows that as the magnification increases for a given eyepiece design, the field of view shrinks.

This observing session will have familiarised you with the magnifications and field sizes for your two eyepieces. These will be useful data as we plan our observations of other celestial bodies.

Alas, observing the Moon while it is full is the absolute worst time to see many of its most inspiring features. To see the great mountains, valleys, craters and rilles; we’ll have to wait until the Moon proceeds through its last quarter and crescent phases. We shall return in a few days when it begins to wane.

Be sure to tune in again soon; you won’t be disappointed!

Date: February 5 2018

Time: 00:35UT

Conditions: good, steady conditions, almost totally clear, cold.

Temperature: −1C

I’ve been watching the Super Ball!

No, that’s not a typo!

It’s a lovely winter night here in the glen. The Moon began to rise about 10:30pm local time, but I waited a couple of hours before beginning observations of the waning gibbous Moon. Charging the telescope with the 25mm Explorer eyepiece, I watched in sheer amazement as our wonderful natural satellite rose above the tree line in the east. Even with the 28x eyepiece, there was a wealth of fine detail to be seen. At low altitudes the air roils quite a bit. That’s totally normal. At low altitudes, you are looking through a dense swathe of air, which generates a bit of turbulence. At these low altitudes, you can even make out subtle colour differences in the lunar regolith. Specifically, the Moon takes on a very light, rose tint. This is also to be expected, as at lower altitudes there is more dust which scatters blue light more than red (a phenomenon called Rayleigh scattering). I find it very beautiful! Compare its colour again when it rises a lot higher in the sky. That comely rose tint all but disappears. Only its silvery face presents itself when it rises above the dust line.

Below is an image of how you should see this waning gibbous in the low power field of your 3″ reflector. I simply rotated and inverted a Wiki Commons image of the Moon at this stage in its phase. That said, I perceive the contrast in the telescopic image to be noticeably better than this image.

The waning Gibbous Moon as seen in the low power eyepiece of the telescope.

As the minutes pass, the Moon rises higher and the image becomes steadier. When it reaches a decent height, say 15 degrees or so, remove the low power eyepiece and insert the 10mm ocular, delivering 70x. The image should remain nice and crisp and even more detail should be discernible. Use a Moon map to try to identify some of the sights your eye meets with. As the Moon rises above 30 degrees altitude (so about one third of the way from the horizon to the zenith), use a Barlow lens to boost the power still more. If the optics are working half decently and are properly aligned, you ought to get good sharp images at 150x or higher, if the air remains steady. That the images are crisp and clean even at these high powers testifies to the extraordinary value of this economical little telescope.

Intriguingly, February 2018 will not have a full Moon (it will be almost full though lol); something that hasn’t happened since 1999. And, as if in recompense, March 2018 will have two full Moons; one on the 1st and the other on the 31st. So March 2018 will present another Blue Moon if you’ve missed the apparition in January.

I like to name all my telescopes. This little one is called Oona.

Wee Oona; ready for action.

Date: February 6 2018

If you follow the phases of the Moon faithfully with the little Space Probe 3 telescope, you’re sure to have an absolute ball. It will serve up beautiful images time and time again. Arguably the best times to observe our natural satellite is between the half−illuminated and crescent phases. You will be astonished at just how much this instrument can reveal!

When taking the telescope and your eyepieces from the cold night air back inside to a warm indoor space, chances are you’ll notice that some condensation may form on the optical surfaces, in much the same way as steam from a kettle fogs up a cold window. This effect of fogging up is more inconvenient than anything else, but you can largely avoid it by capping your eyepieces and the telescope before you bring them back indoors. Under no circumstances are you to rub the lenses or the mirrors while they have dew on them. If you see signs of condensation, just let it evaporate away before capping up the optics. These simple measures will ensure that your equipment will remain in top condition for many years to come.

Observing the Moon is only the first step in enjoying the Orion SpaceProbe 3. As we shall discover, a rich variety of celestial objects are within easy reach of this little telescope. All we need is another clear sky to explore them.

The Ever Changing Sky

The Northern sky on February evenings.

The night sky is constantly changing; minute by minute and hour by hour, as the world turns on its axis and races around the Sun. Consulting the all−sky maps presented on pages 30 and 31 of Ridpath and Tirion’s book, you can see how the February sky appears in the northern hemisphere. Looking south, we see Virgo, Leo, Cancer, Gemini and Taurus, as if in some grand procession, moving from east to west. Concentrating on the constellation of Cancer, the celestial Crab, featured on page 97, I have selected a single object worth investigating with the telescope; The Beehive Cluster (M 44).

The constellation of Gemini in our guide book. M 44 is seen circled near the centre of the consellation.

The accompanying notes featured on page 96 give us enough background information in order to make sense of what the telescope will reveal. M 44 is an open cluster, also known as Praesepe (the Manger), the authors inform us. It is large, covering about 1.5 degrees, and consists of some 50 stars ranging in glory from magnitude 6 and fainter. It even tells us how far away the cluster is; a mind−boggling 592 light years according to measurements made by the Hipparcos satellite. It ought to be visible to the naked eye as “misty patch” from a dark country sky, making it easy to track down.

Time: 23:00−23:30 UT

Seeing: Good, clear, cold.

Temperature: −3C

I took the telescope out for a short spell tonight after work. It remained very clear all day, and on into the evening. It was another lovely vigil with a light dusting of fresh snow to brighten up the landscape. So, before the Moon came up, I ventured out when I knew the cluster would be highest in the sky, that is, when it’s due south. Where I live, M44 is a very easy naked eye object. Just like the authors described, it’s a fairly conspicuous “misty patch” that is easily framed in the finder ‘scope and the main telescope proper. Only one eyepiece was used tonight; the 25mm Explorer II, delivering 28x. It framed the cluster perfectly, where dozens of stars of various degrees of glory pepper the field of view. And it’s not at all hard to see why its more popular name, the Beehive Cluster, is alive and well. With a little concentration, you can make out a soft, yellow colour in the brighter members; a good sign that this cluster is fairly mature in the scheme of things. I made a simple sketch of what it looked like (see below). If you are warm and comfortable, sketching can be a whole lot of fun, even in the cold of winter. I simply try to memorise what the field is like for 10 or 15 minutes, nudging the telescope along with one finger as the Earth rotates beneath my feet. Once I’m indoors I make the sketch. Little Oona frames lots of things in the sky very well.

There are, of course, other ways to make a sketch. Many do so while at the telescope. In order to do that, it’s advisable to protect your night vision as much as possible. You see, in the dark, your pupils dilate to take in as much light as possible. This is a natural biological response to low light conditions. Fortunately, red light does not appreciably interfere with this dark adaptation, and so many amateurs choose to make their telescopic sketches of deep sky objects under the illumination of a low intensity red light source. Whatever way you choose to carry out your sketches, I hope you will find the activity both relaxing and rewarding.

Date: February 8 2018

Some Musings on Optics

Anyone who has spent a decent amount of time with this telescope and knows how to keep the optics well aligned will surely tell you that the images are exceptional for its meagre monetary value. The reason for the low cost is the simplicity of the optics. The prmary mirror is spherical rather than a true parabola. Spherical surfaces are much easier to execute well in comparison to their parabolic counterparts, which need further figuring to ‘deepen’ the centre of the mirror. But if its aperture is kept small and the focal length is large in comparison, there is absolutely no need to modify the sphere into a parabolic shape. To get an idea of just how good a 76mm (3″) mirror with a focal length of 700mm can be, take a look at a computation made by OSLO (an optics package);

An OSLO analysis of a perfect 76mm f/9.2 spherical mirror. The reader should concentrate on the red underlined data in the lower box.

If your mirror is a perfect sphere then you have a wavefront rating of 1/12.5 PV. Put another way, a completely error free mirror with these specifications would have a Strehl ratio (seen on the right above) of 1.0. The analysis shows that the actual value is shockingly close to absolute perfection: 0.97!

The conclusion is very simple to interpret: small aperture and long focal length spheres are so close to a parabola it makes little difference.

Of course, we also need to consider the aberrations introduced by the secondary mirror, but suffice it to say that unless the secondary is a complete lemon, it’s very likely that the overall quality of the optics will be very high indeed, good enough to impress anyone who takes the time to spend a few hours with it.

Star testing provides a good way to test how well the optics behave in the field. To do this, make sure the telescope has accurately aligned optics and has had time to cool down outside. Next, select a bright, first magnitude star, situated high up in the sky. For example, Capella is just perfect from my far northerly location. Select a high power; anything between 100x and 150x and carefully focus it. You ought to see a tiny sphere (the so called Airy disk).

The Orion Spaceprobe telescope supports the secondary mirror using a 3 vane spider (b above) and yields six diffraction spikes that are very hard to see except round the brightest stars.

Now, if you slowly rack the focuser inward, you will begin to see a set of concentric, Fraunhofer diffraction rings around a dark central spot.The shadow of the three spider vanes will also be seen.

And when you then rack the focuser outward, past the position of precise focus, the diffraction pattern should look identical (or almost so). This is what you want to see in a telescope offering very good to excellent optics. Star testing can provide much information about your telescope, but it’s always best to conduct such tests under the best conditions your local environment will provide, and (preferably) over a few nights. If you don’t get such textbook perfect results, don’t fret. I mean, if you’re already happy with the high power images your telescope is serving up during the day, and again by night, you have a winner and you needn’t worry any more.

Oona star tests very well, showing that her optics are of very high quality. Mass production has clearly come a long way with these little telescopes!

Date: February 9 2018

Time: 19:15 UT

Temperature: 0C

Conditions: good transparency, mostly clear, breezy

Orion is a majestic constellation to explore with a small telescope.

It was a bright and clear day today and the the sky has remained largely cloudless after dark. The mighty constellation of Orion the Hunter is now approaching its highest point in the sky so is nearly due south. It will present a good opportunity to examine an entirely different kind of deep sky object. Tonight, we will pay a visit to the Great Nebula in Orion. Our guide book on page 197 shows me exactly where to look: immediately beneath the middle star in the Hunter’s belt. The notes of page 198 inform me of some sensational facts about this target; the object, known also as M 42, is a gigantic ball of gas lit up by young stars that are forming inside it. The authors say M 42 lies about 1500 light years away and that it is almost 20 light years across, and much more. Time to set up the telescope once again for another adventure under the stars.

Time: 20:30UT

The Great Nebula in Orion is also easy to spot with the naked eye. A couple of seconds of scrutiny will convince you that it is quite unstarlike; more like another ‘misty patch’ than anything else. Starting with the 25mm Explorer II eyepiece, the telescope clearly reveals its nebular nature in a pretty hinterland of bright stars. If you carefully focus on the nebula, the same eyepiece should allow you to just make out four distinct stars at the centre; this is the famous Trapezium; very young and hots stars that are estimated to be only a few million years old. They formed out of the cool gas that surrounds them. Ordinarily, a gas cloud is not luminous in and of itself. It is only by virtue of the radiation from the stars that form inside it that renders it visible, just like a neon light bulb.

Now switch to the 10mm Explorer II ocular for a better view of this magnificent structure. At 70x, it is much easier to see the four stars making up the Trapezium, as well as much greater detail in the nebula itself. My eyes can clearly discern colour within the nebula; a very pale green. The colour becomes easier to discern as one’s eyes adapt to the darkness. The visual colour of M 42 is quite unlike that produced by a CCD camera however, which picks up vivid blues, pink and red, owing to its greater sensitivity to light. Still, just detecting some colour provides a real visual thrill.

Just to the north of M42, my eye meets with a ‘fuzzy’ star. This is in fact another nebula; M 43. After several minutes of study, slowly nudging the telescope along as the object moves westwards through the field, I made a quick sketch of my impression of the view as seen through the little 3″ reflector.

M 42 as observed on the evening of February 9 2018 using the 76mm f/9.2 reflector. South is at the top and west is to the left.

Larger telescopes will give even more compelling views. That’s because larger telescopes collect more light and deliver that light to your eyes. A fully dark adapted human eye allows your pupil to dilate to about six or seven millimetres. That is the maximum ‘aperture’ of the human eye. But when you look through the telescope, that 7mm is replaced by a mirror fully 76 mm in diameter! As you can imagine, it collects many times more light than you can with your naked eye because its light collecting area is so much greater; and that allows you to see much fainter objects.

The orion SpaceProbe 3; a wonderful little light cup.

Date: February 11 2018

Time: 21:10−21:20 UT

Conditions: turbulent, frequent sleet & snow showers, very cold in the wind.

Temperature: −1C

Oona(right, background), accompanied by Octavius, my newly flocked and insulated 8−inch f/6 Newtonian reflector.

I spent Saturday afternoon lining the inside of my 8 inch f/6 Newtonian reflector with cork and then covered it over with flocking paper. This evening, I decided to test drive the 8 inch, which I had planned to use along side the 3 inch reflector, but the frequent interruptions from snow showers forced me to retire the larger instrument after about 15 minutes; I did however gather some useful data on a few tricky double stars.

Because the 3 inch telescope is so lightweight and ultraportable, it was the ideal instrument to use in these very mercurial conditions. And it allowed me to greatly extend my gaze. Everything we have visited thus far with the 3 inch reflector lies entirely within our own galaxy, the Milky Way. Tonight though, I spied the Plough asterism looming large in the northeastern sky and decided to try my hand at tracking down the famous Messier duo, M 81 & M 82; a wonderful pair of galaxies located at a distance nearly four orders of magnitude further away than even the Great Nebula in Orion!

Charting a course.

The pair is easy to track down in a dark, moonless sky. Consulting my guide book on page 251, I was able to chart a course for these fairly easily, by drawing an imaginary line from Phecda through Dubhe, and extending that line about twice as far again until I arrived at my destination. Tucked away in an otherwise fairly barren sector of the firmament, my finder could easily make out 7th magnitude M 81, and, with a wee bit more concentration, M 82 also. Once again, only one eyepiece was used this evening; the trusty 25mm Explorer II eyepiece, which easily framed the duo, separated as they are by about 0.6 angular degrees of sky. M 81 looks fuzzy and elliptical in shape, brightest near its centre and gradually fading towards its edges. M 82 to its north presents as completely different however; more cigar shaped than elliptical. After a while studying the pair, you may come away thinking that M 82 is easier to study, even though it is about four times fainter than M 81. Both galaxies lie at a distance of 12 million light years; an utterly unfathomable scale.

I made a quick sketch, shown below, of M81 and M 82, and its hinterland through the SpaceProbe.

Messier 81 & 82, as seen through the 3″ f/9.2 reflector on the evening of February 11 2018.

There are many more galaxes within reach of the little achromatic, and which will take us even further afield. Best to wait ’til better weather sets in though.

Date: February 14 2018

Time: 20:40UT

Temperature: 4C

Conditions: Mostly clear, some cloud interfering with observations, milder than of late, windy.

After enjoying a romantic Valentine’s supper together with my wife, I ventured outside to see how the sky was shaping up, and as luck would have it, it seemed very inviting to continue our adventures under the stars with the Orion SpaceProbe. As promised, we’re going to try our hand at objects significantly farther away than our former targets; specifically, a trio of galaxies in the constellation of Leo the Celestial Lion, which will be very well placed later this evening. These galaxies are located about three times farther away than either M 81or M 82, so about 35 million light years distant from our galaxy, the Milky Way.

Our targets tonight are located in southern Leo, shown just above the tip of the pencil in this photo.

Consulting my guide book on page 169, I can clearly see the location of these galaxies; M 95, M 96 and M 105; which should be captured in the low power (28x) field of the 3 inch telescope. That said, these ‘island universes’ are considerably fainter than M 81 & M 82 and so will be a bit more challenging to see (my guide book quotes both M 96 and M 105 as having a magnitude +9, whereas M 95 is fainter still at + 10).

I shall report back later to tell you how I got on. Fingers crossed!

Time: 23:45UT

Alas, it has totally clouded over, so I will need to abort this activity tonight and try again another night.

Date: February 15 2018

Time: 14:00 UT

The weather is not always in harmony with human ambition. Meteorology may be a mature science, but it can’t yet be relied on with 100 per cent accuracy. There will always be discrepancies between what the forecast predicts and what you actually experience. It just comes with the territory of any amateur astronomer. That said, such episodes cultivate patience and preparedness; virtues in their own right.

It is a New Moon today, so a thin crescent should appear in the sky over the coming evenings. But once that Moon sets, it will be good and dark enough to ferret out those galaxies in Leo. I will report back again as soon as an opportunity presents itself.

Date: February 16 2018

Time: 00:30UT

Conditions: quite windy, some clear spells, remaining more mild than of late.

Temperature: +4C

I managed a short spell with the SpaceProbe just after midnight. By then, Leo had moved into a favourable position in the south southeast. I centered the finder ‘scope on the star 53 Leonis, which lies just south of the targets in an otherwise rather empty region of sky. Then, charging the 3 inch with the 25mm Explorer II eyepiece, I nudged the telescope about one angular degree to the north norhwest and scrutinised the field for signs of faint fuzzies. Sure enough, both M 95 and M 96 show up well in the little SpaceProbe at 28x. The more easterly M 96 is slightly brighter than M 95. The latter appears rather circular with a noticeable central condensation. To my eye, the fainter M 96 looks a wee bit more elongated along its north−south axis. Both of these objects are classed as barred spiral galaxies. Moving this pair to the southern edge of the field, your eye will pick up the giant elliptical galaxy M 105, appearing as a faint glow.

Although the strong gusts of wind and the constant interruption from clouds prevented me staying out for very long, you can visit another delightful trio of galaxies directly east of these objects; specifically M65, M66 and NGC 3628, also featured on the map above. All shining with magnitudes of about 9, they present as an equally challenging target for the 3 inch reflector. Do give them a visit if your skies permit.

Date: February 20 2018

Time: 14:00 UT

We’ve only just begun to sample the riches of the deep sky with the 3 inch reflector. By studying the maps provided in the guide book, you can explore many more, and all in their due season. The more you use the instrument, the more proficient you will become at finding these objects in the night sky.

I would now like to call your attention to an exceedingly rich cache of double and multiple star systems that can be studied with this little reflector. These objects are a particular favourite of mine, so I hope you will indulge me a little.

The world of double and multiple star systems.

On page 282 & 283 of our guide book, the authors discuss these fascinating objects. Our star, the Sun, is alone, but many stars in the firmanent, perhaps the majority, occur in so−called binary or multiple star systems, where each component is bound up by the gravitational attraction of its other stellar members. A few, as we shall discover, are not true binaries at all. They just happen to be situated very close to each other from our vantage but are not actually physically connected. Such targets are called optical doubles.

Like the many other classes of deep sky objects, double stars come in a variety of levels of difficulty; from the easy to difficult. Fortunately, the easiest double and multiple stars to see through the Orion SpaceProbe are also amongst the most beautiful. If the weather cooperates this evening, we’ll take our first steps into this fascinating sub−discipline of amateur astronomy.

Diviner of double and multiple stars.

Time: 22:45−23:15 UT

Conditions; Cold, partially clouded over, decent clear spells.

Temperature: 0C

I managed a few simple drawings of some double and multiple stars near the north ceslestial pole. I had intended to sketch Castor A & B but was clouded out before getting to it. I will discuss these systems later.

Some simple sketches of double stars in and around the pole.

The above drawings reveal some easy double and multiple star targets near the north celestial pole. Where I live at 56 degrees north latitude, all of these systems are within easy reach, owing to their high altitude. Mizar is the middle star in the Plough handle, now situated high in the eastern sky. Closer naked eye scrutiny reveals that it has a fainter companion, but you’ll get a very pleasant surprise when you examine the system telescopically. For this you will need to use the 10mm eyepiece (70x) as indicated in the sketch, but you should clearly see that Mizar itself is also double! It is without doubt one of the northern sky’s most celebrated double stars. Curiously, astronomers have discovered that although they appear to be co−located, there is no physical connection between them. Indeed, on page 252 of our guide book, Mizar is found to be 86 light years away and Alcor just 82 light years distant. Thus, we are looking at an optical double here. However, the close−in companion to Mizar is a bona fide companion. This was the first telescopic double ever to be discovered in the history of astronomy, being first sighted by Giovanni Riccioli in 1650.

In my sketch I have also recorded the faint star with a very lofty sounding name, Sidus Ludovicianum, situated between Mizar and Alcor. It is of note only because an intrepid 18th century German stargazer believed it was a new planet and, as was the custom in those days, named it after Ludwig V, his monarch.

Polaris, the pole star, is a completely different animal though. In the low power (25mm) eyepiece, it appears as creamy white star, but if you crank up the power to 70x or higher and closely scrutinise the space in the immediate vicinity of the star you will eventually notice a tiny, faint spark over 250 times fainter than the main star! You might want to increase the power that little bit more with a Barlow lens in order to see it even more distinctly. This is another true member of a gravitationally bound multiple star system, the other constiuents being too difficult to pick up in the little 3 inch reflector. Polaris A and B lie at a distance of 433 light years according to our guide book. Interestingly, Polaris A is a giant pulsating star known to astronomers as a Cepheid Variable. By studying this class of star, astronomers were finally able to elucidate the vast distances to the nearby galaxies beyond the Milky Way in the early decades of the 20th century.

Note: did you notice Polaris moves much more slowly in the telescopic field? Puzzled? Well, that’s because it lies less than one angular degree from the north celestial pole, the rotation axis around which all the stars in the northern hemisphere appear to whirl. This rather convenient position means it is so much easier to study using the undriven mount of the SpaceProbe 3.

Moving into Canes Venatici (see page 99 of the guide book), yet another showpiece double is ripe for viewing. The brighter member appears white to the eye at 158x and the fainter looks more electric blue to my eye, though reports differ significantly between observers. Indeed, no two observers will report precisely the same colours! This system lies 115 light years away.

Date: February 22 2018

Time: 23:18

Temperature: +1C

Conditions: Cold, hazy skies, good seeing.

I had to tie up some loose ends and couldn’t come back to this as early as I had planned, but I made up for it somewhat this evening. Below are two further sketches I made at the eyepiece of the Orion SpaceProbe 3. The first is Castor A & B in Gemini. Using the map on page 153, I was easily able to pinpoint Castor high in the southern sky at 22:00UT. Centring the star in the 25mm eyepiece, I switched to the 10mm and was delighted to see that even at 70x, the components were well split. But you’ll get a much more majestic view if you crank up the power still more, and, like I said before, this telescope takes high power in its stride because its optics are very good indeed. If your sky is good, test it at 210x and I guarantee you’ll be gobsmacked by what you see!

Both Castor A & B appear pure white as the driven snow, and are quite close together; significantly closer than any system we have thus far visited. More on this tomorrow.

An observation of the close double star system Castor A & B, as seen on the evening of February 22 2018 through the 3 inch Orion reflector.

As the night marched on, the skies became steadily more hazy and visibility suffered as a result. But I spied Leo coming into a good position in the southeastern sky. Using the map on 169 of our guide book, I was able to pinpoint the fairly bright star gamma Leonis (or Algieba, in Arabic parlance) and after centring the star in the 28x field, I one again cranked up the power to 70x and was delighted to see that, like Castor A and B, it too was duplicitous. The brighter member (primary) shines with a golden countenance, while the secondary component appears yellow−green to my eye in this telescope. They are exceptionally handsome in the instrument at 210x. The system lies about 110 light years away and our guide book informs us that they orbit their common centre of gravity in just over 500 years!

Wow!

I made a sketch of this system too in the high power field of the 3 inch reflector, pictured below.

An elegant communion of suns, courtesy of your Creator.

Perhaps you noticed that in the high power field of 210x, both Castor A & B and Gamma Leonis appear to be separated by about the same angular distance. Just how close they are will be the subject matter of my next discussion.

See you soon.

Date: February 23 2018

Time: 14:00 UT

A word on the stellar magnitude scale: The stars in our guide book are divided up on a scale of magnitude, first devised by the 2nd century BC Greek astronomer, Hipparchus. He found it convenient to divide up the glory of the stars into six magnitudes, ranging from the brighest stars (magnitude 1) down to the faintest (magnitude 6) stars that could be seen with the naked eye. This rather arbitray assignment of brightness was improved on in the middle of 19th century of the common era, when the English astronomer, Normon Pogson, defined magnitude 1 stars as being precisely 100 times brighter than those of magnitude 6. Roughly speaking, a first magnitude star will be about 2.5 times brighter than a 2nd magnitude star, and these in turn are 2.5 times brighter than stars of the third magnitude, and so on. On this scale, there are stars that are actually brighter than magnitude 1 and are assigned either magnitude zero or a number less than zero. For example, the brightest star in all the heavens is Sirius, shining with a brightness of −1.46! This scale has the advantage of being able to be extended in both directions; brighter objects take on a greater negative magnitude, while stars fainter than magnitude 6 are assigned brightnesses with greater positive values. In this scheme of things, the Sun shines with a dazzling brightness of −26.7! Our guide book depicts stars of varying brightness with different sizes, going from the largest (brightest) to the smallest(faintest).

Angular measurement as it applies to double stars: As mentioned yesterday evening, the Orion Spaceprobe 3 showed us stars that were separated by various amounts of dark space. To see how close these separations are we must first take note of how angles are measured in astronomy. Recall the full Moon in the sky. This conspicuous orb subtends an angle of 0.5 degrees, but when we spied the small list of double stars discussed above, the telescope was able to resolve things separated by much smaller angles. For convenience, one angular degree is further divided into 60 arc minutes, so using this scale, the full Moon spans 30 arc minutes. One arc minute is depicted as 1′. Now each arc minute, in turn, is further divided into 60 arc seconds (depicted as 60″).

So 1.0 degree = 60′ = 3600″.

Using this new scale, we can begin to explore how much the stars in the above sketches are separated by. The companion to Mizar, for example is separated from its primary by 14″, but the two tightest pairs thus far examined; Gamma Leonis and Castor A & B have much smaller separations; of the order of just 4″ or so. But just how much finer can our little telescope resolve? For double stars, we have a well established rule of thumb devised by the Victorian mateur astronomer, William Rutter Dawes, who suggested that the the limit is given by the simpe formula called the Dawes Limit: 4.56/ D where D is the aperture of the telescope in inches. Thus, for the 3 inch SpaceProbe, we ought to be able to resolve pairs separted by as little as 4.56/3 = 1.5″. The reader will note that as the diameter of the telescope is increased so does its resolving power. A 6 inch aperture ought to resolve pairs roughly half as small again.

There are a few qualifications we have to make with this formula. For one thing, Dawes devised it for two 6th magnitude stars of equal brightness. Things get more difficult as the brighness difference between the components becomes greater. Simply put, the greater the difference in brightness, the greater the angular separation needed to resolve them. What is more, if the stars are blue and equally faint, separations a little smaller than 1.5″ becomes possible. What’s more, the small obstruction made by the telescope’s secondary mirror (which we learn is just 19.9mm as stated on page 8 of the telescope instruction manual) also tends the shift the maximum resolving power a little upwards to more than 1.5″. Finally, these considerations are strictly true only for resolving stellar targets; as we shall see, the telescope will be able to resolve considearbly finer details on extended objects like the Moon and planets.

Small telescopes such as the Orion SpaceProbe 3(laevo) and the Shortube 80 make dapper double star ‘scopes.

These qualifications will help us to gauge how well the little reflector will do in due course. But for now, we have more double stars to visit

A Brief Aside: Return to the Moon

Time: 19:30UT

The Moon is now at first quarter and very high up in the southern sky. This is an ideal opportunity to see just how well the little Orion SpaceProbe 3 can perform. After examining its surface at 28x and 70x, feel free to crank up the power to 150x or 210x and note how well the image bears up. Right now you will see amazing details in the crater fields, the Apennine Mountain range and much much more. It’s at times like this that you will come to appreciate just how good this telescope is. Enjoy the ride!

Date: February 24 2018

Temperature: 0C

Time: 21:45UT

It was a beautiful bright day here in the glen but it remains unusually cold. After a very hazy night last night, transparency improved a great deal today and I set up the little telescope at sunset to enjoy wonderful details on the brightening Moon. Seeing remained exceptionally good, as evidenced by very steady high power views of the Moon and double stars using a couple of larger telescopes I had also deployed to make the most of the unusually good conditions.

Beginning at about 6:45pm local time, I began to make observations of three rather delicate stellar systems; Rigel (Beta Orionis) easily seen as the exceptionally bright white star in the extreme southwest of the constellation. The SpaceProbe showed its very faint companion just off to the southsouthwest of the primary. Although I caught a glimpse of it at 70x using the 10mm Explorer II eyepiece, I elected to boost the power to 158x using my 2.25x Barlow lens and was rewarded with an even better view. Although Rigel B is situated about 9″ away from its primary, the enormous brightness differential makes it far more challenging than it looks on paper.

Immediately after that, I moved the telescope east into Monoceros (featured on page 187 of our guide book) by using Orion’s downward sloping belt stars as a pointer. I quickly centred Beta Monocerotis in the low power eyepiece. Then I switched to 210x by inserting the 10mm ocular with my 3x Barlow and was rewarded by a wonderful sight. Here is a magnificent triple star system (sketched below). The reader will note that the B and C components of this system are just 2.9″ apart, so significantly finer than anything we’ve thus far explored. Another triple system can be found in Cassiopeia (see the map on page 109). You can find it by making an imaginary line from Ruchbah through Eta and extending that line about the same distance again until you come to a creamy white magnitude +4.6 star, Iota Cassiopeiae. Using a power of 210x, the 3″ SpaceProbe showed me an even more beautiful and delicate arrangement of three stars. The C component is easier to see owing to its greater distance from A but the B component is also just under 3″ from the latter.

Below are some simple sketches I made for clarity.

Observations of delicate multiple stars as seen with the 3″ Orion SpaceProbe on the fine evening of Saturday, February 24 2018.

You can take it from me that these systems are challenging for obervers with significantly larger ‘scopes, so I hope you will agree that the 3″ Spaceprobe is a most capable high resolution instrument.

Date: February 26 2018

Time: 00:10UT

Just as I was about to pack up my 8 inch and 3 inch Newtonians at the end of an excellent vigil under the stars at 23:30UT on Saturday, February 25, I spied a couple of stars in Ursa Major, now very high up in the south southeastern sky, indicated by the position of the pencil tip in the image below (page 251 of our guide book).

On the march.

Specifically, I went in search of a star called Xi Ursae Majoris, also known by the rather charming appellation of Alula Australis. After centring the star in the low power 28x eyepiece, I once again cranked up the magnification on the 3 inch SpaceProbe to 210x, carefully focused and was rewarded with a beautiful, sharp image of a pair of yellow suns, the primary shining at magnitude 4.3 and the secondary, just a half a magnitude fainter at magnitude + 4.8. What is MOST interesting about this system is that they are currently separated by just 2″, so we’re getting awfully close to the double star resolving limit of a 3 inch (76mm) telescope. This pair of stars move fairly rapidly, completing one orbit of their centre of gravity in just under 60 years! The reader will also note that this was the first visual double to have its orbit calculated by Felix Savary back in 1828.

I made a sketch (below) of what I saw in the SpaceProbe. The stars are orientated roughly north to south.

Xi Ursae Majoris; testing the mettle of the little long focus Newtonian.

Date: February 27 2018

Time: 00:05UT

Temperature: −2C

Seeing: Remaining very good, very bright waxing gibbous Moon, virtually cloudless sky.

We are stuck in very cold, Arctic−like weather which meteorologists have dubbed, “the beast from the east” lol. At this late hour, the eastern sky is now showing the wonderful Spring constellation of Bootes. This constellation is home to a veritable treasure trove of interesting double stars. The other night, I got my first gander through my larger 130mm f/5 Newtonian of one of my all time favourite colour constrast double stars; Epsilon Bootis, or Izar, discussed on pages 90 though 92 in our guide book. Despite the presence of a very bright gibbous Moon, its shines fairly prominently at magnitude + 2.5, so is easy to find even from an urban location.

Bootes is home to some fine double stars, choicest among them being Izar, indicated by the pencil tip in the map on page 91 of our guide book.

Shortly after midnight local time, it had a reached a decent altitude above the eastern horizon, so I decided to investigate what was what with the 3 inch telescope. In the low power (28x) field, the star looks singular with a comely orange hue. But when I increased the power to 210x, I was once again delighted to see its greenish companion fairly effortlessly in the fine winter air. Now, while the pair is separated by about 3″, there is a fairly large difference in brightness between the components; the primary being +2.6 and the secondary only +4.8. Thus, there is a 2.2 magnitude differential between the components, making it more challenging than it looks on paper. The Orion SpaceProbe is turning out to be a most excellent double star telescope that even veteran observers will appreciate!

I made a drawing of what I saw in the eyepiece for reference (shown below).

My sketch of Epsilon Bootis in the high power field of the Orion SpaceProbe 3 telescope.

Date: February 28 2018

Time: 17:45 UT

Snowmageddon.

The beast fae the east is here the noo. Shockeroonie!

The elements are arrayed against us.

Cannae see heehaw, ken.

Date: March 1 2018

Time: 14:15 UT

We endured freezing, blizzard conditions (the worst in the country) throughout last night, bringing at least 30cm of snow. The high winds have created dangerous drifts of fine, powdery snow, making the roads all but impossible to travel on. But we have a warm fire, plenty of food and water, and our spirits remain high.

Small telescopes are very popular choices for observing the Sun, the star that sustains all life on Earth. I thought about how I might use the SpaceProbe 3 to do some solar observing when Spring properly arrives. Two methods came to mind: the projection technique and the use of a white light solar filter. The former involves pointing the telescope, fitted with an eyepiece, at the Sun and using some white card to project a focused image of the solar disk in order that I could record the presence of sunspots(regions of high magnetic intensity on the surface of the Sun). But I didn’t want to risk damaging the telescope with excess reflected heat (even a small aperture telescope like this can generate dangerous levels of heat), so I thought about using a white light solar filter as an alternative strategy.

Since I already owned and use an inexpensive white light solar filter with my Shorttube 80 achromat, I wondered whether or not it would fit onto the Spacerobe 3 optical tube.

The white light solar filter used with my Short tube 80 achromat fits snugly on the SpaceProbe 3 telescope!

Well, it was like finding money in the pocket of an old jacket lol! The filter fitted snuggly over the front of the instrument! It was the perfect fit! Now I can observe the glory of our star in perfect safety. The tall tripod upon which the telescope sits is a good height off the ground, allowing any ground thermals to be kept at bay. This should make an excellent little solar telescope but I shall have to wait until this severe weather leaves our shores before more testing can be done.

The filter works by rejecting 99.999 per cent of the incident solar radiation, passing only a tiny fraction of the Sun’s light to the eye.

That being said, it is of paramount importance that the reader heed this warning:

NEVER LOOK AT THE SUN THROUGH ANY OPTICAL INSTRUMENT AS PERMANENT BLINDNESS WILL RESULT!

Date: March 2 2018

Time: 13:15 UT

If you plan to use the SpaceProbe 3 to observe the Sun on a regular baisis, it pays to remember that the most economical way of acquiring a solar filter is to make one yourself. There are many outlets that sell various kinds of polymers specifically designed to reject the vast majority of the Sun’s light and heat. Perhaps the best of all is the very well established Astrosolar Material, marketed by Baader Planetarium. You can purchase a sheath of this material for under £20 UK and use it to make your own, homemade filter. Here is a link to one such DIY project.

22:00UT

A Request:

Attention Experienced Telescopists!

I’d appreciate if someone were to follow up on the reports thus far communicated. It’ll take up a little bit of your free time, but I think you’d get a kick out of it.

Date: March 7 2018

Time: 15:20UT

Sol seeker.

Well, after a week long hiatus owing to terrible winter weather, the Sun briefly poked its brilliant rays through the clouds and I was finally able to see if the solar filter worked as advertised. I can report that the Spaceprobe 3 did an admiral job of focusing the solar disk sharply using the 10mm Explorer II eyepiece. Because the Sun’s disk is precisely the same size as the full Moon, it takes up the same area of the field.The reader will note that the small finder ‘scope objective was covered during the observation, so as to prevent any potential accidents! See, you have to think ahead when observing our star!

Was there anything to see?

No! Lol!

Though I’m certainly not a diehard solar observer, I’ve never seen it so completely devoid of sunspots! That’s not to say that there are no sunspots on its surface only that they were beyond the detection limits of this small telescope on this occasion. That having been said, there is no reason why a would−be user of the Orion Spaceprobe 3 could not use this as a very effective white light solar telescope; adding to the versatility of the instrument.

Curiously, low sunspot activity is somewhat correlated with cold spells, so in a way, this was not completely unexpected.

Taking stock: By now, I’ve demonstrated just a tiny number of things in the heavens that are accessible to this excellent little telescope. And the sky’s really the limit! By studying the constelattions that are well placed in your local skies, you could spend many happy months and years exploring a host of other deep sky objects, as well as the glories of the Moon and never once feel you’re missing anything. And once you’re done, you can always visit them all over again, each in its proper season. Soon, you’ll find that they become old friends! Such is the atitude of a determined telescopist!

I would like to end this blog by exploring something completely different; a planet dwarfing the Earth in size and majesty, hurtling ’round the Sun beyond the snowline of the solar system. I speak of none other than mighty Jupiter. More on this soon.

A Brief Daylight Experiment

Comparing the image sharpness and light gathering power of the Orion SpaceProbe 3 with a stopped down 90mm f/5.5 ED apochromat.

Introduction: On Sunday afternoon, I set up both the Orion SpaceProbe 3 f/9.2 Newtonian alongside a high quality 90mm ED f/5.5 apochromatic refractor during a bright spell in order to estimate the light gathering power of the Newtonian and also to compare and contrast image sharpness in both instruments. Both telescopes were kept out of direct sunlight, so as to miminise thermal effects.

Materials and Methods: I constructed three aperture masks of progressively larger aperture from cardboard. These had diameters of 56mm, 65mm and 73mm, respectively. The masks were affixed using parcel tape, placed ahead of the dew shield of the refractor and carefully centred on the optical train. Starting with the 56mm aperture mask, I compared the images of the denuded branches of a horse chestnut tree about 100 yards in the distance in both telescopes. I charged the ED refractor with a Vixen HR 2.4mm ocular delivering 208x diameters. A 2” Tele Vue Everbrite diagonal (99% reflectivity) was used to maximise image brightness in the refractor. The Orion SpaceProbe 3 reflector was charged with a 7.5mm Parks Gold coupled to a 2.25x Barlow delivering 210x. The experiment was repeated using the 65mm and 73mm aperture masks on the refractor and the views similarly compared. My wife also volunteered to assess the images and our findings were in good agreement.

Making the aperture masks: left to right: 56mm, 65mm and 73mm, respectively.

Results: There was a clear and unequivocal difference between the images when the refractor was fitted with the 56mm aperture mask. The SpaceProbe 3 delivered a noticeably brighter image but image sharpness was quite comparable.

The masks are easily affixed to the front of the refractor using parcel tape.

Using the 65mm aperture mask, the results were much more comparable, with the refractor yielding a slightly brighter image but image sharpness was still quite comparable. Finally, when the 73mm aperture mask was affixed, the refractor produced the brighter image although image sharpness remained quite comparable.

Locked on a stationary target.

The Vixen HR 2.4mm ocular with a 2″ Tele Vue Everbrite diagonal.

Conclusions: The 76mm SpaceProbe reflector has a light gathering power equivalent to a high quality quality 60 to 65mm refractor. Image sharpness is right up there with the apochromat in these daylight tests. That’s a very good result for a telescope that retails for less than £70 delivered to your door. In comparison, a top quality 60 to 65mm Apo (without a diagonal, eyepieces or mount) could set you back between £400 and £800!

Final note: We sent our results to former Sky & Telescope Associate Editor, Tony Flanders, whose opinion I trust, and who has also evaluated the Orion Space Probe 3 in a past review. He agreed with our assessment.

Some readers may legitimately ask why a 76mm reflector would not be as good as the equivalent sized refractor. The answer lies in the way these telescopes are designed. The refractor uses a lens to collect light and its transmission is very efficient. Mirrors are not quite as good though, since they reflect a high percentage of the light which strikes them, though not all. For example, if the mirrors both reflect say, 85 per cent of light incident upon them, then the percentage of light that reaches the eye will only be 85 per cent of 85 per cent; that is 72 per cent. Add in the small amount of light lost by the obstructing effect of the secondary mirror and you can begin to appreciate why it is not as efficient as the same size refractor. Having said all that, the little reflector still collects enough light for you to enjoy many objects in the heavens, as we have discovered.

Date: April 1 2018

Time: 20:45 UT

Temperature: 0C

Conditions: Good clear sky, no wind, steady conditions.

An Encounter with Venus

It remains unseasonably cold. Indeed, more snow is forecast for tomorrow. I can’t help but think that this is in part attributed to the solar sunspot minimum that is upon us just now. Nevertheless, the light on the landscape and the lengthening days inform me that April is truly here, lol.

At dusk, I set up the little Orion SpaceProbe 3 reflector at the side of the house to observe Venus, which appeared like an intensely bright star sinking into the western sky. Venus is now an evening ‘star’. Excitedly, I turned the telescope on the planet, charging the instrument with the 10mm Explorer II eyepiece delivering 70 diameters. Well, the strongly gibbous disk of the planet was clearly visible, but it was completely featureless. Increasing the power to 140x didn’t really help things all that much. You see, you can discern very little on the Cytherean disk in any telescope, however large and powerful. But what I could see was the six diffraction spikes emanating outward from the brilliant white planet. I found these very striking and quite beautiful to behold. As mentioned previously, this six−pronged diffraction spike is produced as a consequence of the secondary mirrors three spider vanes. In contrast, the view in my larger Newtonians shows cruciform diffraction spikes owing to the four spider vanes supporting their secondary mirrors.

At present, Venus is at its smallest; just 10 arc seconds in size. It is much larger when it is in its crescent phase and slowly shrinks as more and more of the disk is revealed. Venus, like our Moon, goes through phases!

Venus is covered in quite good detail on pages 348 through 352 of our guide book. And though it looks serene through the telescope, you wouldn’t want to be there. Indeed, it is the nearest thing to a proverbial hell that humans could possibly imagine. Its choking atmosphere of carbon dioxide has generated a massive, run−away greenhouse effect that has raised the temperatures on the surface to about 470C; so hotter than any domestic oven! The atmosphere exerts a pressure in excess of 90 times that found on the Earth at sea level, and then, to add insult to injury, the clouds are not made of cooling water vapour as they are on our world, but instead are composed of droplets of sulphuric acid with a concentration of about 80 per cent. Anyone standing on its surface would be simultaneously crushed, choked, incinerated and corroded to death! Not a pleasant prospect methinks.

But Venus was not created for life, whereas the Earth was.

Thank goodness for small mercies!

I made a drawing of what I saw at the telescope.

Venus as seen through the 3 inch SpaceProbe Newtonian on the evening of April 1 2018.

An Encounter with Jupiter:

Studying Jupiter from the guide book.

Date: April 28 2018

Time: 01:30am

Temperature: 3C

Conditions: mostly clear, bright gibbous Moon now sinking into the southwestern sky, rather cool.

This morning, I enjoyed my very first telescopic observation of the giant planet Jupiter in 2018 as it approached the meridian. I very much wanted to begin this season of observations using the Orion SpaceProbe 3 reflector. And boy was I not disappointed! To see it well, I had to move the telescope(on its mount) across the road to the children’s play park so that I could get a good view of the planet as it hung over the trees like a distant coach lamp. But that was never an issue, as the set up is so lightweight that transporting it over the 80 yards of so was not an issue.

Charging the telescope with the 10mm Explorer II eyepiece, the telescope delivered an excellent panoramic view of the planet at 70x with its four large satellites; Io, Europa, Ganymede and Callisto. Even at this power, I was able to see that the planet was flattened at its poles. This is caused by the planet’s rapid rotation on its axis, taking less than 10 hours to complete one revolution. As a result, its equator bulges owing to fierce centrifugal forces, which also somewhat flattens the poles. Jupiter’s shape is thus best described as an oblate spheroid.

Using the 2.25x Barlow with the 10mm eyepiece yielded a power of 158x, but while this gave a sharp image, I found that a better image was obtained by backing down on the magnification in order to optimise resolution, contrast and image scale. I reached for my 1.6x Barlow with the 10mm Explorer giving a power of 112x. This gave a wondeful image! I was able to make out the tan coloured equatorial belts and also a few other belts at more northerly and southern latitudes (maybe 5 bands in all?). I could also make out significant detail within the equatorial belts. Studying the image from minute to minute, I tracked the planet simply by nudging the telescope along, applying gentle, finger pressure to the optical tube.

Having observed and enjoyed the Giant Planet in many small telescopes over the years, I can report that the 3″ f/9.2 Newtonian provided an image that was significantlty more detailed than a classic, long focus 60mm refractor and was more reminiscent of the details garnered by a very high quality 66mm William Optics triplet apochromatic refractor I had the pleasure of owning many years ago. The SpaceProbe 3 will definitely allow you to study this planet, and with some practice, you will be able to make out other features, such as the famous Great Red Spot(GRS), an enormous, terracotta brick−coloured storm that has persisted on the planet for at least the last few centuries. Such tempests last much longer on this world owing to its lack of a solid surface, which causes terrestrial storms to abate quickly as they get drained of energy when they fall over land. Every now and then (but not on this occasion), one or more of the satellites crosses in front of the planet allowing you to see a disk shaped shadow of the same moon projected onto the cloud tops of this giant world. When you see such an event, it will most assuredly take your breath away!

A light blue Wratten no 82 filter is a good tool to enhance belt detail on Jupiter.

I watched the planet until it culminated in the south after 2:00 am local time, when it reached the same altitude as Rigel (so not very high) does in my local skies, and was delighted by the high quality images this simple, inexpensive telescope served up. As an experiment, I screwed on a light blue Wratten filter to the same eyepiece/Barlow combination and found that this filter improved the contrast between the dark belts and brighter zones of Jovian atmosphere. I would advise other observers to try this filter (which can be picked up for just a few pounds).The planetary image in the telescope was quite stable and relatively devoid of turbulence in comparison to larger aperture instruments. That’s because small aperture ‘scopes such as the SpaceProbe 3 are relatively insensitive to the vagaries of the atmosphere and are quite well suited to low altitude planetary observations.

I left the field tired but genuinely impressed with how well the telescope showed this fascinating target. I even made a quick sketch of the panormaic view at 70x but hope to make a full disk drawing of Jupiter in due course.

You can find out much more about Jupiter and its satellite system by consulting pages 362 through 367 of our guide book.

The mighty planet Jupiter, as it appeared in the Orion Spaceprobe 3 telescope in the wee small hours of April 28 2018.

Date: May 19 2018

Time: 23:45UT

This evening I set up the Orion Spaceprobe 3 reflector to have a look at Jupiter and was delighted to see that the Great Red Spot was prominent near the central meridian (the planet’s north−south line). I made a quick sketch (shown below) of what I saw using the 10mm Explorer II ocular supplied with the telescope coupled to a 1.6x Barlow yielding a power of 112x and a Wratten no 82A light blue filter. Having a hoot with this charming little telescope!

Jupiter with its main belts and zones and the Great Red Spot(GRS) near the planet’s central meridian, as seen through the 76mm f/9.2 Orion Spaceprobe reflector. Local time: 23:4o UT.

Spotting the GRS proved rather easy for this telescope even without the filter, its distinctive colour being readily detected.This is an instrument that will certainly allow you to study the constantly changing aspects of this fascinating world. And with more practice, you will become adept at recording its subtle features.

Conclusions

Three cheers for Oona.

We have now come to the end of this journey with the Orion Spaceprobe 3 altazimuth reflector. As I’ve demonstrated, you can accomplish a great deal with the instrument on the Moon, bright planets, the Sun and into the depths of the deep sky. I feel very privileged to have acquired this simple little telescope and it will remain in my stable.

I hope you have enjoyed this blog.

Keep looking up!

Neil.

Neil English is author of several books on amateur telescopes.

De Fideli.

Neil English.net

Gratia non Superbia

Author Archives: Neil English

An Observing Report from the English Lake District.

Living without Lasers

Focusing on Focusers.

Sampling the Skies in Ireland with a 5.1 inch Newtonian.

Going from Strength to Strength: the 130mm f/5 Newtonian.

Observing in Twilight.

De Rerum Natura

Acts 7:48-50

Dissolving the Fermi Paradox

Paradigm Shifts.

The “Foot” ‘Scope Project: Part II

Further Adventures with a 3″ Achromatic..