I decided to take a shot on observing Saturday night in the Sierra foothills at Fiddletown, although when I met up with Randy Muller and Gary Manning at the Pokerville market the skies were clearly overcast with a mixture of low soupy clouds and high cirrus. When we arrived at the observing site, the only one set up was Ray Cash and apparently we had just missed Rashad who had decided to pack it in after a clear night on Friday. Ray mentioned the sky was clear just a few hours earlier and had deteriorated only recently. After setting up around sunset, conditions noticeably improved and by 7:00 the sky was amazingly clear. Unfortunately, we had bands of clouds that kept passing through at regular intervals with clear spells of perhaps an hour at a time. I was in the mood for planetaries with the highlight of capturing Pease 1 - the first planetary discovered within a globular (there are three others including one in M22, but the others are virtually unobservable).
First up was NGC 6886, a compact PN in Sagitta which was easily identified by blinking at 100x using an OIII filter as a "soft" mag 11 star. A small disc <10" diameter was visible at 220x without filter. This object is situated at the NW vertex of a small isosceles triangle with a mag 11 star 0.8' SSE and a mag 10 star 1.6' E. The nearer star is double with a faint companion close north. NGC 6886 was clearly nonstellar at 280x-380x and slightly oval. This planetary has a very high surface brightness, so should be easy to identify by blinking in small scopes.
NGC 7354 in Cepheus is a fairly bright, 25" disc, which was picked up at 100x with one or two stars very close. At 280x, the PN was slightly elongated E-W, ~25"x20". A mag 14 star is close off the SW edge, 30" from center and a mag 14.5 star is 0.6' due W. At 380x, a mag 15-15.5 star is 0.6' WNW and the surface brightness is noticeably irregular with hints of brighter areas.
Next I took a look at a few Abell planetaries that I hadn't seen in several years. Abell 2 (PK 122-4.1) is a 14th magnitude blur situated at 00 45 36 +57 57.4 just 5' S of mag 8.3 SAO 21680. At 100x using an OIII filter it appeared faint, fairly small, round, 30" diameter. It was visible steadily at 220x using a UHC filter as a well-defined disc. I thought it appeared brighter along the south edge but the DSS shows this was probably due to a faint star superimposed on the south rim.
Abell 4 has a remarkable location -- just 40' ESE of the center of M34, but very faint at V = 14.5. I swept up this object at 100x using the OIII filter as a very faint, round, 20" disc. The PN forms the NW vertex of an obtuse triangle with mag 8.7 SAO 38305 3' SE and a mag 10.5 star 1.6' SE. The best view was at 220x-280x using a UHC filter when it was visible steadily with averted vision as a crisp-edged disc of low even surface brightness. At these powers the planetary could be glimpsed unfiltered.
Abell 12 (PK 198-6.1) would probably not be a very difficult target if it wasn't for its location -- buried within the glow of naked-eye mag 4 Mu Orionis (3 degrees NE of Betelgeuse). At 100x using an OIII filter Abell 12 was easily visible as a round knot bulging off the NW edge of Mu. I had a nice view at 280x with a UHC filter. The PN was fairly well-defined, ~30" in diameter and just resolved from Mu although glare from the star was very distracting. At 380x, Abell 12 was fairly well separated from the glare although no longer crisp-edged due to the seeing.
Pease 1 is one of only four known PNe within globulars and the only one which is a reasonable target in 12-inch and up scopes (V = 15, size = 1"). A good finder chart is a necessity, though, as the planetary is located is just 25" from the center of M15! At 380x (with an equatorial platform) and a detailed finder chart it was not difficult to identify a quartet consisting of two easy pairs of mag 14 stars located 1.5' NW of the center. Getting a feel for the scale in the eyepiece compared to the finder chart, I next identified a 30" string of three or four mag 14.5 stars ~50" NE of the center. Pease 1 is situated midway between this string and the center of the nucleus. At 500x, the precise location was pinned down within a small unresolved clump of stars at the edge of the nucleus 25" NE of center. Blinking with a UHC filter (which dramatically dimmed the cluster), revealed a definite brightening at the NE edge of this clump. With extended viewing this brightening sharpened to a stellar point several times, particularly with the filter attached!
I did take a look at a few galaxy groups including Abell 2666 in Pegasus which includes several faint NGC galaxies -- N7765, N7766, N7767, N7768. My target for this evening, though, was MCG +4-56-14 at 23 50 47.5 +27 17 16 which is located 9' north of NGC 7768 (the brightest member in the core). The MCG galaxy is a member of the rare class of collisional ring galaxies (the "Cartwheel" galaxy is perhaps the best-known member of this class), formed when one galaxy passes through the core of another. The galaxy appeared as a very faint, round glow, ~25" diameter, even surface brightness. Although you can see the "ring" on the DSS, the galaxy was too faint to see any unusual structure. Not bad for a night that had looked so unpromising!