My goal for the night was to attempt observations of three Snow galaxy clusters. I noticed #s 6, 9, & 20 listed in the Interstellarum Deep Sky Atlas index, and wondered what they were. I could not find anything about them on the internet, except for T.P. Snow’s original paper in the April 1970 Astronomical Journal, listing 34 southern galaxy clusters found on the plates from the Yale-Columbia southern proper-motion program—the same which Klemola used for his better-known list of objects. Somehow they meet the criteria the Interstellarum editors used to select objects for the atlas. I followed the SIMBAD link on the SAO/NASA webpage for J2000 positions of the clusters (the paper had 1875 coordinates), and I used IRSA to generate field charts.
My star hop starting point was NGC 247, an impressive, large, but low surface brightness galaxy in Cetus. I nudged my scope a few minutes NNE to see Burbidge’s Chain (VV 518), a line of four small MCG galaxies. I could see three components – a, b, and c. MCG-4-3-10 = a was easy, small, yet the largest and brightest of the group, with an evenly bright core slightly elongated NE-SW, 14.4 mag. MCG-4-3-13 = b was on the other end of the chain; it is smaller than a, round, 14.6 mag., and also picked up easily. MCG-4-3-11 = c was nearby to b, seen averted vision only held about 70% of the time once noticed; 15.7 mag. MCG-4-3-12 = d was not seen; it is closer to a in the chain, and very small and too faint for me, 17.0 mag. Being able to see Burbidge’s Chain gave me some hope I might see something of the Snow galaxies, but more importantly gave me something to gauge galaxy size and brightness by, since the brightest members of the Snow galaxies are 15-16th magnitude – so I should expect marginal observations at best. I star-hopped to Snow 6 first; it is further west and I needed to catch it before it set.
Snow 6 (centered at J2000 00 17 37.0 -24 17 36): With averted vision picked up one small, very faint round glow, which I later found to be MGC-04-01-29 (15.81B, 0.933’x0.747) – which is 7.8” north of where the cluster is centered (the darkest splotch to the upper center of the image below). Since Snow’s paper gives the magnitude range of 16-19B, it is not likely this is a cluster member [Steve Gottlieb later advised Snow’s coordinates were off a little; this galaxy should be the brightest member of the group]. There were some very faint small stars in the field, but not galaxies. I tried 333x and 553x, but still only had the one galaxy. Aladin shows a string of three very small and faint galaxies to the east of the cluster center and to the east of the MGC I saw, but these are well beyond my scope.
Snow 9 (centered at J2000 00 30 22.0 -22 58 12): I searched the area earnestly with averted vision but can only say I suspected two excessively faint very small glows – which unfortunately I can’t correspond my sketch to my finder chart image. This was a “no show”
Snow 20 (centered at J2000 05 19 48.0 -25 17 00, near M79): I waited until Lepus culminated before attempting this one. It turned out to be the most engaging, as it is framed to the north by IC 408 and to the southeast by IC 411, both of which were very plain at 333x 0.3° TFOV. In the below image IC 408 is cut in half at the upper center, and IC 411 is to the center left. I centered my view near the bright star (HD 34895 – which appears as an optical double) at the center of the image, and strained my eyes with averted vision. I had the strong impression of a glow between this star and IC 411, and another glow to the west of the star. 553x strengthened the impression but did not resolve any galaxies. Kevin, a far more experienced observer than me, had the same “feeling” and called it a “maybe.” Aladin shows galaxies in these areas but they are 16-17th magnitude.
After finishing Snow 6 and 9, I had one more interesting observation to make in that region:
WLM (UGCA 444) & WLM 1: Wolf-Lundmark-Melotte is an irregular dwarf galaxy in the Local Group but far enough away from the others to not feel the exertion of the Group’s gravitational forces. Since it has not been jostled so much, forcing new star birth, it is thought most of its star formation occurred 13 billion years ago. It appeared as a large, ill-defined, low surface brightness oblong glow orientated N-S. There are several faint stars superimposed on the galaxy and around its halo. One of these is actually a globular cluster in the dwarf’s pull, WLM1. Using a finder chart to identify the correct point of light, it popped in and out with averted vision and seeing conditions, I could only hold it a moment or two; at 533x it was non-stellar. According to studies, the metallicity of the globular indicates its age is 15 billion years – which is amazing, if difficult, to comprehend.
I moved up to the end of Cetus’ tail, near Alpha Ceti “Menkar”, to make observations from there back to the relatively barren area from the tail into western Taurus:
NGC 1153: Bright, quasi-stellar nucleus, 3:2 NW-SE, small diffuse halo. There is a star on the SW rim of the core, which I didn’t notice – likely confusing it with the nucleus. This is part of a group of seven galaxies—only one of which would be beyond reach of my scope—which SIMBAD calls ACO 403; the group includes UGC 2446 & UGC 2441.
UGC 2446: Small, faint, slightly brighter core; very slightly elongated W-E. (0.677’x0.42’, 14.4B)
UGC 2441: Very faint glow, brightens with averted vision. 3:1 NE-SW, fairly small, near brighter star. In the center of a string of four stars running N-S. [DSS shows a nice edge on with a star below the nucleus. 2.3’x0.368’, 15.0B. The MAC galaxy was not seen]
NGC 1128-1 & -2: Overlapping or very close small round glows, each with bright cores, very small and faint. These are a pair of galaxies and are part of AGC 400. There were two other very small, extremely faint round patches glimpsed with averted vision in the field: to the SW (2MASX J02573365+0558371 15.1B) and to the south (MCG+01-08-028 15.7B). I suspected another one to the NE but not sure. Someday, I need to go into the AGCs better prepared, with finders, and really spend more time tracking components down.
NGC 1218: Fairly faint, round, stellar nucleus and diffuse edge halo. Halo mottled to south and north – could be a spiral? [It is an S0a Seyfert I – 397 mly away!]
IC 302: Fairly faint, fairly large diffuse glow, halo is round and mottled, with a bright small core, 3:1 N-S. Star just off southern tip of halo. [DSS shows a lovely face on spiral, 13.81B, SBc, 2.6:1.1]
IC 315: Very small, very faint, low / even surface brightness glow, brightens overall with averted vision; very slightly elongated NE-SW. Finely split, equal magnitude double star to the NW.
IC 1918: Small, very faint elliptical glow, even brightness, very slightly elongated NW-SE. Near an asterism of six stars shaped like a kite to the west. 427 mly distant – quite far! It must be very intrinsically bright.
IC 1918: Small, very faint oval, diffuse halo; semi-stellar nucleus. In the center of a triangle of stars. It is a LINEAR-type Active Galaxy Nucleus, 304 mly distant; may have a supermassive black hole creating the LINEAR emission lines. In any case a lot of energy output.
Now it was time to view Snow 20. Here is the detail description of the ICs around it:
IC 408: Fairly bright, pretty small, oblong glow with gradually brighter core. Brightens with averted vision. Faintly elongated halo NW-SE. Close to VX Lep, which is 5’ to the SW.
IC 411: Fairly bright, small, round, compact brighter core with diffuse edges. 438 mly.
After straining for Snow 20 as above, I rewarded myself with a look at something bright:
M79: at 333x, pretty large, overall wedge shaped with ragged ends to the north. Well resolved to the round, compact bright core. A prominent star chain runs N-S through the west side of the cluster, with a shorter chain in tangent to the eastern rim. Remarkable for being 41 kly from earth and 61 kly from the galactic center. It is thought not to be native to the Milky Way but a capture from the Canis Major Dwarf Galaxy.
Next, I had a look at galaxies in Orion. Naturally most of us view Orion’s nebulae, but I thought I would spend some time with the galaxies to make them less lonely. I took a quick look at M42 then swung slightly west:
NGC 1924: Bright, pretty large, oval NW-SE, slightly mottled – must be a spiral. UHC seemed to lighten up a knot in the northern rim of the halo. Brighter, small core. [It is a lovely face on SBbc spiral, 1.6’x1.2’, 12.5V]
IC 421: Fairly faint, pretty large diffuse glow, mostly even surface brightness. It’s another impressive face on spiral in DSS. This was a Willamina Flemming discovery on a photographic plate; her boss Edward Pickering published the discovery and took credit for it in the IC.
MCG-1-14-12: Very faint, small, round, diffuse glow. Inside a triangle of similar magnitude stars. Another face on spiral, this one with disrupted arms.
UGCA 102 = Mrk 1094: Very small oval, gradually brighter to middle, pretty faint. It’s a blue compact galaxy, which [cribbed from Wikipedia] are often low mass, low metallicity, dust-free objects. Because they are dust-free and contain a large number of hot, young stars, they are often blue in optical and ultraviolet colors – and indeed the DSS image shows a bluish galaxy. They are not necessarily young galaxies; they might have been “well mixed” and thus efficiently used up its dust during its initial star forming period. Many show signs of recent interactions with other galaxies, and in DSS UGCA 102 does show some warping (its morphological classification is not straightforward: SABcd).
HGC 31: Hickson galaxy cluster. Component a & c was seen as a single irregular glow, not split. Component b was clearly seen, though small, very faint, slightly elongated. Component d, 18th magnitude, was not seen. I also noticed what I thought was a miscellaneous galaxy to the east of the star which is itself east of a/c—but find this is simply a poorly resolved star.
Mac 21, Planetary Nebula: Small, pretty faint, stellar, bluish, blinks with OIII. I can't find any online references to this one.
UGC 3271 = Mrk 1095: Very faint, very diffuse small 3:2 NNE-SSW glow with a small but bright quasi-stellar nucleus. A line of stars runs out from each tip in line with the major axis. It is a Seyfert 1 galaxy, which have quasar-like nuclei—which can be as bright as all the light output from a galaxy like the Milky Way. 444 million light years distant! And such a bright nucleus!
UGC 3258: Small, fairly faint, 3:2 N-S, quasi-stellar nucleus with star on northern tip. SBbc 12.9v. DSS image shows this as almost a ring galaxy, with perhaps a very bright knot on the northern rim? SIMBAD says it belongs in a cluster of galaxies but I don’t see which one…
NGC 1762: Small, fairly faint, stellar nucleus, 2:1 diffuse halo N-S; star on eastern rim. A Sc spiral, and a William Herschel discovery.
CGCG-395-16: Lozenge shape 3:2 glow, gradually brighter to middle. I guessed a star was superimposed on the east rim but find in the DSS image it looks like a very bright knot running along this edge. It lies in a triangle of bright stars, one of which is STF 654. This needed to be out of the view for me to pick up the galaxy, but once seen I could hold the galaxy with the 4.62 magnitude STF 654A in view; the double is well split, yellow and yellow orange 8.5 magnitude B, 7”.
IC 413 & 412: at 333x, IC 413 is fairly faint, small, has a bright core & very faint but clearly disrupted halo. IC 412 right next to it [34”], faint and also small, and seems to be an interacting system. Star very near the northern edge. [It is indeed interacting, VV 225 – and tidal tail north of IC 412 might be visible with more concentration – need to revisit].
IC 414: Very faint glow picked up with averted vision at first, then could just hold directly. Pretty small, obround, even surface brightness.
CGCG-421-27 = Arp 52: Extremely faint, small, round glow with some mottling, brighter in the middle. I did not notice the even smaller near companion galaxy. 390 mly distant.
IC 409: Quickly picked up direct vision, small, fairly faint oval glow, gradually brighter to middle, mottled. [This has five 15-16 B magnitude siblings, which if I had taken more care to explore the surrounding field might’ve noticed.]
HGC 34 = Arp 327: The brightest component, a, is NGC 1875 and was round, very faint, very small. After looking at my Hickson guide photo, I tried very hard to see the very small 17-18B mag b-d components; at 553x I still could not make them out; I had a feeling of an excessively faint streak coming off NGC 1875 to the southeast, but this was probably wishful seeing since I had already studied the photo. 419 mly.
After a break I changed directions to the north to take in some galaxies in Ursa Major:
NGC 2805: Astonishing field, and quite a change from viewing many dim objects. NGC 2805 is a large, fairly faint oval, brighter core but without nucleus, mottled – hint of spiral arms [it is an Sc]. 10’ to the NE are three more galaxies: NGC 2820 is a long edge on, pretty bright with a brighter sliver of a core and long tapering tips, ENE-WSW 5:1. At first I thought the SW tip had a hook to it pointed SE, but this is IC 2458, a small, faint elongation, and it overlaps the 2820’s SW tip, like the Hockey Stick galaxy (NGC 4656/57 in Canes Venatici). NGC 2814 is to the west of this pair, small, faint, elongated 3:1 NNE-SSW, with a star just to its SW. All three are interacting with each other, along with NGC 2880 and IC 2458 which I didn’t observe.
NGC 2880: Stellar nucleus, bright round core, diffuse halo. Rather small, fairly bright, 3:2 NW-SE. In an asterism of nine stars forming a tuning fork, with the galaxy in the fork and the rest pointed NE.
NGC 3079 offered up another amazing view. It is a long, lovely bright edge on 6:1 N-S with plainly seen turned up tips: the southern tip lifts east, the northern tip lifts north-east. This makes it look like the galaxy is descending through space, with the outer parts of the halo being swept upward as it falls. It is a Seyfert 2 galaxy, which accounts for its bright core. NGC 3073 was to the west in the same field, and was pretty bright, small, round, with a bright core and hazy fringes.
NGC 3225: A faint oval, 3:1 NW-SE, moderately small, even surface brightness. Star following on NE rim. It’s an Sc but didn’t show spiral structure in my view.
NGC 2756: Oval, 3:2 N-S. Brighter core, no nucleus. Mottled; seems to be a dark lane running N-S along the eastern hemisphere. [It is an Sb spiral, so this may have been a hint of arms.]
Shakhbazian 98: NGC 2675 was easily visible (pretty faint, small, obround, even surface brightness elliptical) and served, along with a pair of stars to the east, as a finder for the Shk 98 galaxy chain. I searched a while but did not see anything on my own. After checking a finder for the group, which are eight very small and very faint galaxies forming a gentle sickle between the galaxy and pair of stars, I searched again, switching between 333x & 553x. I wish I could say I saw it but no; my eyes were pretty strained at this point in the night.
NGC 3756: Large, 3:2 N-S, fairly bright with a brighter core. The halo is layered like filo dough—striking texture in the halo giving strong impression of wispy spiral arms [ScII]. Double star off the northern tip to the north-west.
NGC 3738 = Arp 234: Rather large, moderately bright, 3:2 NW-SE, with a distinctive tear-drop shape—the core appears brighter and rounder to the NW, while the SE tip curves up from the core and tapers off. Is an active galaxy nucleus.
NGC 3733: 5.6 magnitude star SAO 28064 interferes with the view; the galaxy sprouts from the star as a 3:1 elongated glow NNW-SSE with a slightly brighter core. Too bad; the galaxy is Sc spiral and would probably show nice structure if it weren’t for the star being in the way. Maybe wait a few thousand years for a clearer view!
M97 / NGC 3587: Large, round, bright, mottled with two dark holes, diffuse edges, brighter middle. Star just off the northern rim. Best view with UHC.
NGC 3687: Small, pretty bright, 3:2 N-S. Seems to have a dark lane running its major axis. The whole brightens with averted vision. [As a pretty much face on spiral it should be round; I may have not seen some sections of the outer halo to give it an elongated shape; the dark lane may have been hints of spiral structure.]
NGC 3669: Edge on, 4:1 N-S, gradually brighter to the middle, diffuse edges.
NGC 3642: Round, fairly large, pretty bright, gradually brighter middle and stellar nucleus, diffuse halo. Looks like an elliptical but is an Sb/Sc I.
NGC 3359: Large, generally round diffuse halo, stellar nucleus and a brighter core which runs in a bar NNE-SSW. Halo appears windblown and tattered. It is a SBc II spiral, however I did not discern the arms, only the impression of them.
NGC 3668: Oval, 3:2 NW-SE, moderately bright with brighter core & quasi-stellar nucleus, very mottled halo. Another small, round, faint glow with brighter core is in FOV to east [MCG+11-14-25a, 14.7B 0.62’x0.583’].
NGC 3682: Small, 3:2 W-E, bright elongated core, diffuse edges to halo.
And, lest I forget, Kevin kindly called me over to his scope to share some views. He used a MD 80mm short tube refractor for some wide field. The Witch Head Nebula appeared like a shore of light grey contrasted with the rest of the sky. The California Nebula appeared large and tenuous – I have to say the view in my 10-inch is far brighter (as one would expect with so much more aperture). He was good company and I appreciated him having me over.
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