During some sessions this past new Moon, I targeted four planetary nebulae with the 20" that I had not logged previously. I struck out (sort of) on one of them, but the others were seen. The surprise was MWP 1, the Methuselah Nebula in Cygnus, south of 66 Cygni.
I was not aware of MWP1 until a recent image was posted in a thread by CCDer. The image was beautiful and I wondered why I had not heard of this nebula before. I found the MWP 1 designation and checked Wikisky...and there was nothing there. Zooming out I found something that looked like nebulosity well to the southwest of the position in Wikisky (south of 7th mag HD 202811 rather than east of it.) Although tenuous, the blue hue in the DSS2 images suggested it would respond to an OIII filter, so I decided to give the area a quick look the next time out. Unfortunately, it is not in Uranometria, even under its PK 80-10.1 or PN G80.3-10.4 designations.
Before I get to the observations, let's consider what makes this planetary interesting other than being missing from Uranometria: The moniker "Methusaleh" refers to the extreme age of this nebula, ~150,000 years, ancient for planetary nebula which typically dissipate in a few tens of thousands of years. This makes it one of the oldest planetary nebula known. The shell is now 13x9 arc minutes across, roughly 17 light years wide, at a distance of about 4500 light years. (Link.) The central star is a "PG 1159 star" that is transitioning into the hot portion of the white dwarf stage. The star, RX J2117.1 + 3412, glows at 13.2 V mag at 150,000 degrees. The resulting short wavelength emissions including soft x-rays.
For my first observation I had not researched the nebula, made a finder chart, or even considered where the central star might be in the busy field. Instead I had just marked a spot in Uranometria where I expected the planetary to be. I suspected that the brightest and broadest section of the nebula to the south would have sufficient intensity to be seen with a filter in dark transparent sky (21.70 MPSAS). I started with a 31T5 for 81x and employed a DGM NPB to cover OIII, H-beta, and H-alpha. This worked and I had little trouble seeing this section as a diffuse glow. I then switched to the TeleVue OIII filter to further increase contrast and selectivity if the primary visible emission was OIII. This both confirmed the NPB impression and provided somewhat greater contrast by darkening the surrounding sky.
I researched a little more at home, printed a chart with the central star marked, and returned to MWP 1 again hoping to see the ends of the bipolar arcs east and west. Unfortunately, seeing conditions were poorer and despite trying OIII with the 31, 20, and a 16mm eyepiece I was never certain that I was seeing true nebulosity on either end because of the difficulty of resolving the faintest field stars in the are. I did confirm that I had impressions of some very faint glow extending past the central star, but it was very tenuous. The very blue white central star was easily identified and was even more prominent among the other field stars when filtered.
Contrasting against the very old MWP 1, I observed NGC 7027, a very young planetary nebula that is very small. Somehow I had never targeted it before (at least that I could find record of.) This one has various nicknames including the "Pink Pillow Nebula" (Hubble images), Gummy Bear Nebula, etc. It is small both in apparent size and real size, because it is only about 600 years old. The nebula is unusually massive, 3 to 4 solar masses and is quite intense in brightness, appearing at moderate power as a comatic out of focus star. Higher power revealed a compact boxy object with partitions into three sections with a bright knot in one (preceding edge) that was so intense as to appear to obscure a bright star.
The other fun one was NGC 7048, also in Cygnus. It was bright and easy, of moderate size. At first with 156x and an OIII filter I thought it had some bipolar arcs on one end of the otherwise round body. But employing 227x revealed that one of the extensions was a very faint field star just off one northern edge and the other was embedded field star on the adjacent northern edge. The nebulosity was surprisingly smooth without a prominent annulus.
I targeted IC 5117 in Cygnus twice, but had not reconned it other than looking up a misleading diameter of 12 arc seconds in the Uranometria Deep Sky Field Guide...uhhh, no, try 2 arc seconds. I tried high power, I tried filters, but the problem was I didn't know precisely where it should be in the field, or the actual size, and the seeing was very poor both times I tried...bloating stars to about the same dimension. Upon checking the position more carefully at home, I am certain I saw it, and recognized the asterism that it formed, but I didn't ID it at the time. I also had some indication of the changing relative brightness with an OIII, but I was so frustrated by worsening seeing conditions that I gave up on it.