| Planetary
Nebula
aka PNG 104.2-29.6, PK 104-29.1, ARO 195 Integrated Visual Magnitude: 15.1 Apparent Diameter: 5.3' Magnitude of central star: 16.1 Distance: 2300 ly Actual Diameter: 3.5 ly Minimum requirements to view: 6-inch scope and very dark skies |
You
won't find this faint, low surface brightness nebula in Burnham's or Deep
Sky Wonders. Although visible to very experienced observers as a
round haze in scopes as small as 6-inches under very dark skies, it is
the availability of relatively inexpensive large aperture Dobs and
narrow band filters that has made this sort of low surface brightness object
more generally accessible.
I first tried for this nebula in my 18-inch last year without a filter. In my log I wrote:
This one is hard, even in an 18 inch under dark skies. It appears on photographs as two opposing lobes that presumably make up a "bubble" similar to NGC 246. It's sort of like a much smaller "Cygnus Loop." I used a DSS image to locate the nebulosity. The northern lobe was distinctly visible at 166X with averted vision as a ghostly patch of sky. The southern lobe was more difficult, and only after 45 minutes of chasing it was I able to convince myself that I could see it at all. This one isn't for beginners.More recently I tried it with the aid of an OIII filter. As is often the case for large planetaries, an OIII filter made a dramatic difference. With the OIII in place, what was once only a slight brightening of the sky became a clearly defined broken ring. Two large, opposite sections of this ring stand out as brighter than the rest. With averted vision a faint, round background haze could be seen. I suggest magnifications from 100x to 200x for the best view.
The field in an 18-inch
at 94x. North is down and east is to the right.
| Millennium
Star Atlas Vol III Chart 1162
Sky Atlas 2000 Chart 9 Uranometria 2000 Vol I Chart 124 |
