NGC 7331

NGC 7331, also known as Caldwell 30, is an unbarred spiral galaxy about 43.79 million light-years away in the constellation Pegasus.

In spiral galaxies the central bulge typically co-rotates with the disk but the bulge in the galaxy NGC 7331 is rotating in the opposite direction to the rest of the disk. The core of the galaxy appears to be slightly off-center, with one side of the disk appearing to extend further away from the core than the opposite side.

NGC 7331 Group is also called the Deer Lick Group. It contains four other members, affectionately referred to as the "fleas": the lenticular or unbarred spirals NGC 7335 and NGC 7336, the barred spiral galaxy NGC 7337 and the elliptical galaxy NGC 7340. Although adjacent on the sky, this collection is not a galaxy group, as NGC 7331 itself is not gravitationally associated with the far more distant "fleas".