NGC 7129 and NGC 7142 (APOD 13 Sep 2007)

[Keninho]

In the center of the picture, a little bit to the right, there's what seems to be a comet. Is there any information about it?

[Case]

I suppose it could be a galaxy with a superimposed foreground star. The galaxy might be irregular or partly obscured by dark gas.
If it were a comet, it had to be relatively close to the sun to show a tail.
The tail-like streak appears in other photos of NGC 7129/NGC 7142 at the same location, tho' not as prominent as the APOD one. This rules out comets, as comets move pretty fast.

[Andy Wade]

I suppose it could be a galaxy with a superimposed foreground star. The galaxy might be irregular or partly obscured by dark gas.
If it were a comet, it had to be relatively close to the sun to show a tail.
The tail-like streak appears in other photos of NGC 7129/NGC 7142 at the same location, tho' not as prominent as the APOD one. This rules out comets, as comets move pretty fast.

Given all that I reckon it's a galaxy edge on, that just happens to have a foreground star lining up with one end.

[SmartAZ]

There are many stars and galaxies with tails, looking just like comets. Here is a star called Mira:


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