I was ready to call it quits as far as observing on Friday (April 9) after learning my favorite observing site in the Sierra foothills was under two feet of snow. But the minivan was already packed up and because of the weather the past few months I was feeling desperate enough to give Digger Pines (on the east side of Mt. Hamilton) a last minute chance.
Although the conditions started off pretty mediocre (particularly as it took quite awhile for my 17.5" mirror to reach thermal equilibrium), the skies were perfectly clear and I happily started to work through a number of faint galaxy groups in northern Leo. Perhaps as compensation for recent weather, the sky conditions improved markedly after midnight and by 1:30 they were excellent with sharp images up to 400x.
A few highlights --
Five galaxies were picked up in the galaxy cluster Abell 1213 which is just over the Leo border into Ursa Major at 11 16.5 +29 16. The easiest member to view was MCG +5-27-35, a round 14th magnitude galaxy about 40" in diameter. Just 3.5' north is CGCG 156-39 which required averted and was only half the size.
Surprising, UGC 6292 is listed as the largest and brightest in the core of Abell 1213 (z = .047) but my notes read "extremely faint, 15" diameter, slightly elongated?" Based on the DSS image, it looks like I only observed the small core (the spiral arms have a low surface brightness). A mag 14.5 star is just 1' south of center. There are two 10th magnitude stars in the field and U06202 is located 3' northwest of the preceding mag 10 star.
Less than 5' south of UGC 6292 I picked up MCG +5-27-37, a faint 25" nondescript glow. Finally, 2.5' further east is the close double system comprosed of M+05-27-040 and -041. With averted vision, the pair was just resolved into two very faint, extremely small knots, both ~15" in size [20" between centers].
After I got home I double checked the identifications and positions on NED (http://nedwww.ipac.caltech.edu/) and discovered the first two galaxies in the observation were part of a foreground cluster identified as Abell 1213A (z = .027).
NGC 3615 and NGC 3618 are a 7' pair with an extremely faint galaxy CGCG 126-22 midway between the pair. The brightest in the trio, NGC 3615 was elongated 2:1 SW-NE, roughly 1.2'x0.6' with a prominent 20" core. With direct vision a stellar nucleus stood out. NGC 3618 was just a faint, 1.0' glow with weak concentration collinear with two mag 10 star to the northeast. CGCG 126-22 took some effort and was just glimpsed with averted vision appearing only 10" in diameter.
In 1877 and 1888, there was a telescopic search for a trans-Neptunian planet by David Todd using the 26-inch refractor at the U.S.N.O. Needless to say, he wasn't successful but his published results described 30 "candidates" - compact objects which he made small field sketches and then went back later to reobserve. The NGC only included 8 of these 30 objects because Dreyer considered most of them doubtful or duplicates of previous discoveries. Since Todd's positions were very rough (using setting circles on the refractor) nearly all his discoveries were lost for over 100 years. But Harold Corwin (http://www.ngcic.org) has been able to recover half of Todd's "candidates" which have turned out to be compact galaxies.
NGC 3849 was the 10th object in Todd's notebook but you'll find it today listed as IC 730. I could see why he considered it a planet candidate - faint, small, round, 25" diameter with no concentration.
The Shakhbazian (Shkh) collection consists of 377 extremely faint (member galaxies mag 14-20) compact groups of compact galaxies! The individual galaxies appear very red on the POSS and are generally gas-poor E and S0 types. Only a few of the groups look promising enough on the DSS to resolve even in an 18" scope, but an easy group to locate is Shkh 202 just north of 6th magnitude 9 Comae. Unfortunately another mag 6.7 star is situated smack in the middle of the cluster and of course detracts from viewing these 15th magnitude knots. Fortunately, the seeing was good enough to use 380x and keep the bright star off the edge of the field. The first galaxy I picked up in the field was IC 777, a mag 13.5 oval, about 0.8'x0.4' in PA 160 degrees - but this was just a superimposed foreground galaxy - the cluster was closer to the mag 6.7 and much fainter.
Shkh 202-1 (also CGCG 158-74) is typical of the four compact members viewed - very faint and small, round, ~15" diameter with a fairly high surface brightness. It's situated 5' south of the mag 6.7 star and 3' southeast of a mag 10.5 star. Finally, a second mag 10 star is 6' W. Those stars were a nuisance!
Less than 4' east is Shkh 202-2 (CGCG 158-078) which appeared as a 10-15" round knot at 380x. Shkh 202-3 (CGCG 158-075), another 10"-15" 15th magnitude knot was REALLY poorly placed - just 2.5' south of the mag 6.7 star and 1.4' east of a 10th magnitude star. Finally, Shkh 202-6 was just glimpsed 3.2' northwest of mag 6.7 SAO 82246. This galaxy is the northernmost of 4 members of Shkh 202 viewed. Based on the DSS, there appears to be at least one or two more members I hope to pick up under darker skies.