ASTRO: C179 annotated

As I suspected I wasn't able to fool many of you with how the Andromeda
Galaxy looks much the Milky Way when seen close up and personal.

The cluster I centered on is often seen in shots of the galaxy as a tiny
star, sometimes the HII shows it as pink to the west of M32. Even the
full image is too narrow angle to show the edges of the galaxy let alone
M31.

I'd picked up a few stars in the cluster in a previous image taken about
5 years ago. Ever since I've tried unsuccessfully to resolve it until
this short lived super night of August 29th UTC. Oh yes, it's name. It
has several. In the "Atlas of the Andromeda Galaxy it is cluster C179.
For those who've never heard of the Hodge atlas, it is on line at
http://nedwww.ipac.caltech.edu/level..._contents.html

C179 is one of the largest star clusters in an HII region in the galaxy.
I especially liked the arc of blue stars above it. Is there some
reason for this arc? Wish I knew. Was it created by radiation pressure
from the core stars? Just a random pattern? I have no idea. That's
what it attracts me. NED lists two catalog names for it MESSIER
031:[BA64] 289 and MESSIER 031:[PAV78] 258. Though these refer to the
HII region rather than the cluster. The Atlas mentioned above doesn't
have a section for HII regions so apparently we need both to fully cover
it. Both are part of the stellar association the atlas calls A22.

I've prepared a partial annotated image using the designations in the
atlas and NED when the atlas didn't include the object. C is a cluster,
G a globular and A a stellar association. D is for dark nebula but I
didn't include any of these in the annotated image. Since stellar
associations are hard to identify I've not labeled many of them either.
Both are rather vaguely defined so best seen using the atlas. C179 is
on Chart 5
http://nedwww.ipac.caltech.edu/level...as/Chart5.html. The
image does extend into 3 as well. You can spend a day identifying all
the features. The charts were rather small on my monitor and I had to
blow them up to see them clearly. While most fuzzy blobs are identified
on the atlas as globular and open clusters I've found several that
aren't identified by either the atlas or NED. I put a question mark
beside them. Not all globulars and open clusters are in the atlas, some
I only found in NED. Those carry the NED designation. BOL stands for
Bologna Globular Clusters. Why some aren't on the atlas I don't know,
later data? MLA0469 is an HII region as is [PAV78]274 near it. Only
the former is pink. The latter is associated with an open cluster which
dominates my color data.

Just like it is easy to get lost in the Milky Way you can get lost in
M31 when the image scale is large enough. Having the needed seeing once
in 5 years really makes me envious of those few imaging remotely from
mountain tops where such seeing is routine. Seeing pinpoint stars at
0.5" is a fantastic sight to this imager. I just wish the color data
were up to that quality.

Using NED I was also able to find a handful of very faint planetary
nebula. All but one were close to the noise level making ID a bit
uncertain so I've not listed but two of them, one quite bright on the
left edge of the image. Think how bright it must be to be so easily
seen over more than 2.5 million light years. Even C179 and its HII
region must be a grand sight for those living within a few thousand
light years of it in the galaxy.

14" LX200R @ f/10, L=7x10'x1, RGB=4x10'x3, STL-11000XM, Paramount ME

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".