For 10 points, name this closest spiral galaxy to the Milky Way, named for a mythological princess from Greek mythology.
This object is orbited by Mayall II, which is a globular cluster. Supernova 1885A occurred here. Hubble discovered the first Cepheid variables in this region which has an apparent double nucleus. It is approximately 250,000 (*) light years across and is expected to collide with the Milky Way in several billion years. This member of the local group is item 31 in the Messier catalog. For 10 points, name this closest spiral galaxy to the Milky Way, named for a mythological princess from Greek mythology.
This object is orbited by Mayall II, which is a globular cluster.
{Andromeda} galaxy [or {M31} before "{31}"]