Μ31, also known as the Andromeda Galaxy, is the nearest spiral galaxy to the Milky Way and is located about 2.537 million light-years from Earth. It is one of the largest galaxies in the local group, which includes the Milky Way, Triangulum Galaxy, and several smaller galaxies. The Andromeda Galaxy contains approximately one trillion stars and is expected to collide with the Milky Way in about 4.5 billion years. It is visible to the naked eye from Earth and can be found in the constellation Andromeda, making it a popular target for amateur astronomers.