Andromeda is a constellation named after the princess Andromeda, a character from Greek mythology. Andromeda is the constellation of the northern hemisphere, positioned near Pegasus. Andromeda constellation is best known for the Andromeda galaxy.
The brightest star in the constellation is Alpheratz (Sirrah), which makes the head of Andromeda, and has the Bayer designation Alpha Andromeda. Before this star belong to Andromeda and Pegasus, and was known as the Delta Pegasus. Today, along with the Alpha, Beta and Gama Pegasus makes a great square of Pegasus.
Beta Andromeda is known as Mirach. It is located 200 ly from us and has an apparent brightness of magnitude + 2.1. Gamma Andromeda, or Almach, a double star located 350 ly from us and has an apparent brightness of magnitude + 2.1.
The constellation is best known for the spiral galaxy M31, the Andromeda galaxy. The Andromeda galaxy is one of the furthest objects we can see with the naked eye. It is also our nearest spiral galaxy. The Andromeda Galaxy has a few more satellite galaxies, M32, M110, NGC 147 and NGC 185.