The Andromeda Galaxy is the nearest spiral galaxy to the Milky Way, our galaxy
The Andromeda Galaxy is the nearest spiral galaxy to the Milky Way, our galaxy. Andromeda is sometimes called M31 or NGC 224 by astronomers. It is about 2.6 million light years away from us.
Andromeda is the largest galaxy of the Local Group, which consists of the Andromeda Galaxy, the Milky Way Galaxy, the Triangulum Galaxy, and about 30 other smaller galaxies.
At an apparent magnitude of 3.4, the Andromeda Galaxy is notable for being one of the brightest Messier objects, making it visible to the naked eye on moonless nights even when viewed from areas with moderate light pollution. Although it appears more than six times as wide as the full Moon when photographed through a larger telescope, only the brighter central region is visible to the naked eye. Being both large and bright, it is one of the farthest objects that can be seen without a telescope or binoculars.
Source: Wikipedia