| Planetary
Nebula
PNG 029.2-05.9, PK 029-05.1, ARO 101 Visual Magnitude: 12.5 Apparent Diameter: 10" Minimum requirements to view: 6-inch telescope under country skies |
NGC 6751 () is a 12.5 magnitude, 10" diameter planetary nebula that gained fame recently as a target of the Hubble Space Telescope. NGC 6751 surrounds a 15.4 magnitude central star and lies about 8000 light years distant. In the eyepiece it looks like a tiny version of the famous Ring Nebula.
The above HST image shows the fine structure of this nebula. It won't look like this in the eyepiece of course, but the irregular brighter edge can be glimpsed if you look for it.At low magnification it may at first look starlike, although the star may appear obviously "wrong" somehow. Once you have found the right location, it is important to use high magnification on this small, egg-shaped nebula. It seems to me that the central star is considerably brighter than the 15th magnitude listed. Six to eight inch scopes will show a small egg. Larger scopes will reveal a dark center giving it the appearance of a tiny, faint Ring nebula. Users of larger scopes should also look for the central star.
In May 2000 I observed NGC 6751 with my 18-inch f/4.5 Dob:
This is the view of the field in a 6-inch at 50x.
This is a 12.5 magnitude planetary 20" in diameter. It was obvious at 81x, even though small. The best view came with the 4.8mm Nagler coupled to a 2X barlow (850x). It looked like a small ring nebula surrounding a 15th magnitude star. It seemed to me that the inner portions surrounding the star were darker. This one is small but nice. I liked it.
This image is from the first generation DSS and shows a 5' x 5' field. North is down and east is to the right.
| Millennium
Star Atlas Vol II Chart 1317
Sky Atlas 2000 Chart 16 Uranometria 2000 Vol II Chart 296 |
