Stephan's Quintet and NGC 7331

Stephan's Quintet is the small group of five galaxies at the bottom left of the picture. The blue spiral galaxy to the left is merely in the line of sight. The other four galaxies are very close together and interacting.

NGC 7331 (the brightest galaxy in the picture) is a spiral galaxy of visual magnitude 9.5 and at a distance of 46 million light years. The galaxies in the top right of this picture (including NGC 7331) are often referred to as the Deer Lick Group. It is not a real galaxy group - the fainter galaxies are ten times more distant.

The NGC 7331 spiral reveals a high level of detail despite the galaxies inclination to the line of sight. This galaxy is particularly interesting because it is so similar to our own galaxy. It has about the save size, a similar sized black hole at the centre and the spiral structure is also similar.