Visual astronomy can be enjoyed in a variety of ways. We can use the eyes our Creator designed for us to marvel at the beauty of the night sky. Or we can employ a telescope to get those up-close views, where both resolving and light gathering power are needed to make sense of what we see. But there is also the binocular perspective, which fills a niche set midway between that of the eye and that of the telescope.
On the night of August 25 2019, I found myself doing all three. After an hour of admiring dim and hard to find deep sky objects using my largest telescope; a 12″ f/5 Newtonian reflector, I sat back in my observing chair to drink up the naked eye heavens above me. The air was still, with no wind, and only the occasional screech of a barn owl breaking the silence. After a few months of twilit skies with only the brightest stellar luminaries on display, true darkness had now returned to the landscape. By 11:30pm local time, the bright constellations of Cygnus, Lyra, Hercules and Aquila had passed into the western hemisphere, with Bootes now sinking perilously close to the western horizon. And over in the northeast, Cassiopeia, Perseus and Auriga were making excellent progress climbing ever higher in the sky. Andromeda and Pegasus were also ripe for exploration. The familiar asterism of the Plough hung low over the northern horizon, far below the North Star, Polaris, around which the great dome of the sky wheels. With no Moon in the sky, and good transparency, the river of light from the northern Milky Way stood out boldly, snaking its way across the heavens from east to west. It was the perfect opportunity to break out my big binocular, a Pentax DCF 20 x 60 and boy did it deliver the readies!
As I described at great length in the preamble linked to at the beginning of this blog, the Pentax DCF 20 x 60 combines excellent optics with great mechanical features in a relatively light weight package; ideal for use with a monopod. The instrument attaches in seconds to a strong, high-quality ball and socket mount head and can be transported easily from one place to another. Delivering a pristine, flat field some 2.2 degrees wide, the Pentax had already delivered gorgeous views of the heavens during Winter and Spring evenings, but I had not yet had an opportunity to sample the skies of late Summer/early Autumn with this powerful optical instrument.
My first target was M13, easily found about one third of the way from Eta Herculis to Zeta Herculis in the western edge of the famous Keystone asterism. I had already admired this big and bright globular cluster earlier in the 12″ telescope at high power. The 20 x 60 binocular revealed a bright fuzzy bauble about half the size of the full Moon and neatly sandwiched between two 7th magnitude field stars. Of course, the binocular could not compete with the majesty of such a cluster as presented in a large, light bucket, but it was nonetheless a lovely sight with wonderful contrast against a jet black sky.
I then moved over to Lyra and centered the bright summer luminary, Vega, shining with its intense blue-white hue across the sea of interstellar space, and surrounding it a swarm of fainter suns, including the famous Epsilon Lyrae of double star fame. Moving into Cygnus, I turned the binocular on Beta Cygni, known more commonly as Albireo. With a steady hand, I could easily resolve the beautiful, wide colour contrast double star; marmalade orange and blue-green secondary. Panning about eight degrees due south of Albireo the binocular field soon captured that remarkable little asterism that is the Coathanger (Collinder 339). What makes this a particualrly engaging visual sight is the uniformity of the stars comprising it; most shining with a soft white hue and of the sixth magnitude of glory.
Moving about five degrees to the east of the Coathanger, and forming a neat little right-angled triangle with the stars of Saggita, the celestial Arrow, I chanced upon the large and bright planetary nebula, known commonly as the Dumbbell (Messier 27). Unlike other planetary nebula, M27 is one of the few that present clearly in the relatively low power view of the binocular. Try as I might though, I could not see the hourglass shape of the nebula as seen in telescopes at higher power; it was more or less circular in form, softly glowing against the background sky at magntude 7.4.
I didn’t have to travel far for my next visual treat; M71, a faint globular cluster situated nearly exactly midway between Gamma and Zeta Saggitae. With its population of mostly 12th magnitude suns, M71 presented as a misty patch in a glittering hinterland of August star light.
Adjusting the ball & socket head of the monopod, I ventured back into Cgynus and centred the lovely binocular double, commonly referred to as 0^1 Cygni. Like a wider version of Albireo, the 20 x 60 binocular presented their fetching colours perfectly, orange and turquoise (magnitude 3.8 and 4.8, resepctively). I could not however clearly resolve the fainter 7th magnitude component parked up against the orange member, which a small telescope so easily shows.
Eager to examine another stellar hinterland, I moved the binocular so that Deneb was centred in the field of view. Well, this binocular portal took my breath away! Hundreds of suns of varying degrees of glory smattered haphazardly across the field, and here and there the excellent contrast of the instrument also showed up some small nebulous patches set adrift among the starry hosts. With its very generous 21mm of eye relief, the big binocular was delivering very comfortable and immersive views. It was almost as if I could reach out my hand and touch the heavens!
With midnight approaching, I noticed that the great square of Pegasus was clearing the rooftop of my house, and a little further to the east, Andromeda, the Chained Lady, had by now gained a decent altitude. Eagerly, I trained the binocular on a foggy patch clearly seen with the naked eye. I had arrived at the Great Andromeda Galaxy (M31). The lenticular shaped core was big and bright and beautifully contrasted against a sable sky, and with averted vision it was not hard to trace the spiral arms all the way to the edges of the field. Its fainter companions, M32 and M110, were also seen with a concentrated gaze, the former being easier to see and just a half an angular degree to the south of M31. M110 proved much more elusive though, being larger and fainter than M32 but nonetheless fairly easy to pick off about a degree away to the northwest of the main galaxy.
Moving into Cassiopeia, the binocular presented field after field of brilliant starlight with a wonderful variety of colours. Many faint open clusters came to life as I inched the binocular through its mid-section; NGC 457(otherwise known as the E.T. Cluster) was very engaging, especially the bright, 5th magnitude white super-giant star marking its southern border, and then on into the heart of M103, a compact little open cluster just to the northeast of blue-white Delta Cassiopeiae. My notes from a good few years back informed me that the cluster presented as unresolved in an inexpensive 15 x 70 binocular, but this instrument, with its significantly higher magnification, was just beginning to hint at some individual stars within the cluster. A comely quartet of stars flanking the southeastern corner of the Messier cluster made the scene especially engaging to study. Panning very slowly eastward through the constellation, roughly from Delta to Epsilon Cassiopeiae, my eyes picked up many faint open clusters, including NGC 44, 663, 559 and 637.
By about a quarter past midnight, Perseus had risen to a good height above the northeastern horizon, and I eagerly sought out the famous Double Cluster(Caldwell 14), easily located as a foggy patch to the naked eye roughly mid-way between Perseus and Cassiopeia. With great excitement, I moved in on my target, all the while bringing to mind the stunning views I had reported with this binocular last Winter. Wow! I wasn’t disaapointed. The entire field exploded with stars of various hues; white, blue-white, creamy yellow and sanguine, the two sumptuous open clusters beautifully resolved with curious fans of stars radiating outwards from their centres. Sharpness was extreme from edge to edge, with the stars presenting as tiny pinpoints. I believe that this 20 x 60 binocular renders these awesome natural spectacles as good as you’ll ever see them; the combination of decent light gathering power and magnification using both eyes is a match made in heaven! This was a pre-season teaser though. The Double Cluster will only increase in majesty, as it continues to climb higher in our skies over the next few months.
Moving to Algol, the Demon Star, I then navigated about 5 degrees west from it, where I was pleasantly surprised by how easily I was able to pick up another lovely open cluster, M34. The powerful double eye on the sky resolved a few dozen members, mostly 7th, 8th and 9th magnitude members sprawled across an area of sky roughly the size of the full Moon. Many fainter members, largely unsresolved by the instrument, gave the cluster a very lively, translucent appearance, a consequence I suppose of the inability of the binocular to cleanly resolve its faintest members, which go all the way down to magnitude 13. Sometimes, not seeing things clearly adds to the visual appeal of deep sky objects.
From there, I moved back to Alpha Persei and placed it at the upper edge of the field of view of the 20 x 60. Even though the binocular has a fairly restricted 2.2 degree true field, it was able to pick up a generous assortment of bright O-B stars at the heart of the moving cluster Melotte 20. It was a beautiful sight!
With the time fast approaching 12:30 am, I picked up the 20 x 60 astride its monopod and moved to the front of the house, where my gaze met with the Pleiades rising above the Fintry Hills to the east of my home. Though it was still at a fairly low altitude, the 20 x 60 produced a draw-jopping view of this celebrated open cluster, its orientation being rather lobsided compared with how it appears later in the autumn. Many of its fainter members were extinguished by virtue of its low altitude, but it was still a magnificent sight. Again I would concede that large binoculars produce the best views of the Pleiads. And it will get better, night by night, as Autumn turns to Winter.
With a waning crescent Moon not far away from rising, I retired from the field of glory with a head full of vivid memories. This was just the beginning though. God willing, it will show me even grander sights as the days continue to shorten through the autumnal equinox and onwards toward the December Solstice.
Neil English’s new book, The ShortTube 80, A User’s Guide, will soon be published by Springer-Nature.