Spirograph and Running Man

A couple of nights ago I got a couple more hours in. The seeing turned out to be quite good and the transparency somewhat poor, so I bagged the single PN on my list first:

IC418 Spirograph Nebula 1/28/2009 19:50UT; Pickering 7, NELM 5, SQM 20.4
16" Mak-Cass

Non-stellar at 150x; double shell at 375x. Inner shell quite bright; outer shell averted vision. Central star of moderate difficulty, but direct vision. Central region around star appears brighter most of the time, but not during moments of settled seeing, so I think it's just flare from the star.

Slight egg sahpe more apparent at 450x. Outside edge of inner shell appears "woven", especially under motion, and more-so at 600x. I don't detect any annularity of the inner shell.

My next target was somewhat of a disappointment as I only managed to capture about 1/2 the nebulosity that O'Meara did in "Hidden Treasures" (and he was using all of 4" of aperture, although he did have the advantage of altitude and pristine skies).

On the other hand, my much longer focal length is more similar to instruments used in the 19th C, and if you equate my light pollution to their poorer-quality optics, then my sketch goes a long way toward demonstrating why Herschel (and later Dreyer) gave this nebula 3 separate designations. (Well, that's my story anyway, and I'm sticking to it.)

NGC1977 Running Man Nebula 1/28/2009 20:45UT; Pickering 7, NELM 5, SQM 20.4
16" Mak-Cass

Bright stars in field largely drown out nebula at 150x. DeepSky helps somewhat, revealing a couple of dark lanes and more nebulosity. UHC nearly as good; OIII too aggressive. Larger exit pupil perhaps just a smidgen better, but there's not much in it.

Appears as 3 distinct nebulae, with the two brightest sections of NGC1977 adjacent to its two brightest stars, and somewhat difficult averted vision nebulosity connecting them along the SW edge of the central cluster. An equally bright nucleus of 1973 appears right around its star, and a difficult diffuse glow can be made out in averted vision at the center of 1975 (around and to the SE of the prominent double star).

Next up was, well, some cloud cover....

Cheers,
-- Jeff.