Here's a quick rundown of observing targets from Saturday night at Fiddletown. I was planning to focus on Winter HII regions but was sidetracked (once again) by late fall/early winter galaxy clusters which I enjoy viewing.
One unusual planetary I looked for was Simeiz 22 (also known as PK 128-4.1 and Sh2-188). This huge filamentary complex was discovered at the Simiez observatory in Russia in 1951 and was relisted in a survey by Sharpless in 1959. Jay McNeil provided me with background information on this interesting object. Both Simiez and Sharpless classified this object as an emission object and at one point it was considered both an HII region and a SNR based on its wispy appearance (like a dim version of Pickering's Wedge in the Veil). It wasn't until the 90's that Simeiz 22 first appeared in PNe lists and it is now considered an ancient, crescent-shaped planetary similar to the Medusa Nebula (Abell 21), which coincidentally was one of the last objects I looked at in the evening. The best view of this phantom object was at 100x (20 Nagler) using an OIII filter. With averted vision, a large, low surface brightness glow was visible, elongated ~E-W and perhaps 8' in length with a better defined southern edge. Several mag 13-14 stars are superimposed. It wasn't easy to identify this planetary (definitely not your garden-variety type), so I called Mark Wagner over for confirmation and we compared our visual impressions.
Cetus is home to a number of faint galaxy clusters and I wanted to revisit a small group which included NGC 327 and NGC 329. I last took a look with my 13-inch back in 1986 and picked up the two NGC galaxies as well as MCG -1-3-41. But strangely there were two additional NGC galaxies in the field (NGC 321 and 325) which I missed. This time, with my 17.5-inch, NGC 321 was noted as a "very faint, round knot, 15" diameter, situated 1.4' SE of a mag 12 star." NGC 325 was only a marginal sighting, requiring averted at 280x to occasionally glimpse. I also picked up an additional galaxy, MCG (-1-3-42), which was actually easier than the two NGC galaxies mentioned above! It's hard to see how Albert Marth, who discovered the group from Malta with a 48-inch equatorial (that's right!) in the 1860's missed the brighter MCG galaxies which are just north of the NGC galaxies.
While browsing through John Vicker's excellent CCD atlas a couple of years back, I ran across his image of AGC (Abell Galaxy Cluster) 160 in Pisces at 01 12 59.7 +15 29 29. The *brightest* member, MCG +2-4-10, has a photographic magnitude of 15.7, so I knew this was going to be a challenge. This giant cD galaxy was easily visible at 280x, though it appeared as a featureless 20" glow near two brighter mag 12 and 13 stars about 1' east and north. Just under 5' NNW, CGCG 436-011 (also listed at 15.7) required averted vision and I apparently only glimpsed a 15" core and missed the low surface brightness arms. Also 4' NE of MCG +2-4-10 I picked up M+02-04-011, another ghostly 15" knot which appeared slightly elongated NW-SE and nestled midway between a mag 13.5 star 1' N and a mag 14 star a similar distance south. Finally, after much effort a galaxy with the awkward name NPM1G +15.0044 (a Lick Northern Proper Motion reference galaxy), popped into view at moments, appearing a "soft" mag 16 star.
For a change of pace, IC 1731, which was discovered photographically by Isaac Roberts, was a relatively easy find in Triangulum at 01 50 12.4 +27 11 46. The galaxy itself is a fairly nondescript oval, but the setting is unusual. Just a few arc minutes south is a distintive 5' group of 10 brighter stars mag 8.5-12 including a mag 10 pair at 18". The brighter stars form a rough semicircle open to the east with 5 fainter stars bringing the total to ~15. This group appears to be an asterism but is catalogued as Cr (Collinder) 21.
Back to galaxy clusters, I took another look at HCG 5 (Hickson Compact Group), with brightest member the double galaxy NGC 190 at 00 38 54.7 +07 03 46. This was my third observation of the group was it was initially seen as a single faint, elongated glow at 220x. At 280x in moments of steady seeing NGC 190 cleanly resolved into two very close, very small knots with the brighter component on the N side. HCG 5C was only intermittently visible with averted vision as a 15" threshold knot (listed with a B magnitude of 16.3).
I'm intrigued by this field because 20' SSE is another Abell galaxy cluster! ARC 76 contains three IC galaxies (IC 1565, 1566 and 1568) which are neatly aligned from SW to NE. This time I also picked up members IC 1569, located 15' due east of IC 1565 and UGC 429, 3.0' SE of a mag 10.5 star.
After a quick peek at IC 1953, situated in the same low power field as mag 4.3 Tau 5 Eridani, I star-hopped north to the NGC 1407 group which contains no less than 7 NGC galaxies (1383, 1391, 1393, 1394, 1400, 1402, 1407) as well as IC 343. I've viewed this group with a C-8 in the early '80's as well as with my 13" in the mid-80's, but this time I picked up the fainter members NGC 1391, NGC 1394 and NGC 1402. Both William and John Herschel explored this group but missed these relatively easy galaxies and they were later discovered at the Leander-McCormick observatory in Virginia in the late-1880's with a 26-inch refractor. But then again the Herschels weren't mapping the heavens with the help of DSC's, the Uranometria 2000 and computer generated star charts based on the Hubble Guide Star Catalogue!