Ann wrote:Chris wrote:
It might be a galaxy. Or it might be an unusual form of cluster that simply hasn't been properly classified.
It absolutely doesn't look like a galaxy to me.
Nor to me. But I've seen enough odd things in astronomical images to not allow my visual impression to sway me too much.
I don't trust that there's actually a star halo around this object. I've seen similar illusions.
I don't trust color. We don't consistently see redshift, and in any case, this image is not made from filters which create an image with accurate color.
We don't even have a solid definition for what a galaxy is. There are dwarf and irregular galaxies that overlap globular clusters in size, mass, and composition.
What I know is that this seems to be a peculiar object. It is substantially more elliptical than any other globular cluster I've been able to identify. It appears to have a disc bisecting it (I don't believe this is a diffraction artifact, as there is at least one other object in the image with a similar size which is brighter and has no diffraction artifacts). I think the most likely explanation is that it's either an incompletely formed globular (one model says they form irregular, and become globular because of tidal effects), or a previously globular cluster that has become disrupted.
In any case, we can do little more than make educated guesses until somebody points some instruments that way and collects more data.
I'm way out of my depth here, but it's fun!
) forgot about it. 
