| NGC
6751 |
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 |
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NGC 6751 is a 12.5
magnitude, 10" diameter planetary nebula that gained fame 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.
This is the view of the
field in a 6-inch at 50x.
In May 2000 I observed NGC
6751 with my 18-inch f/4.5 Dob:
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.
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Millennium
Star Atlas Vol II Chart 1317
Sky
Atlas 2000 Chart 16
Uranometria
2000 Vol II Chart 296 |
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