Andromeda
Andromeda (Andromedae)
Andromeda is one of the most prominent constellations in the autumn sky, famous for containing the Andromeda Galaxy (M31), the farthest object visible to the naked eye at approximately 2.5 million light-years away. The constellation extends eastward from the Great Square of Pegasus, forming a chain of stars that represents the mythical princess bound in chains.
📜 Mythology
In Greek mythology, Andromeda was the beautiful daughter of King Cepheus and Queen Cassiopeia of Ethiopia. When Cassiopeia boasted that she was more beautiful than the Nereids (sea nymphs), the enraged Poseidon sent a sea monster called Cetus to ravage the kingdom. To save her people, Andromeda was chained to a rock by the sea as a sacrifice. The hero Perseus, returning from slaying Medusa, spotted the princess, fell in love with her, and rescued her by turning the monster to stone with Medusa's head.
💡 Facts
- ✦The Andromeda Galaxy contains approximately one trillion stars and is approaching our Milky Way at about 110 km/s
- ✦In about 4.5 billion years, the Andromeda Galaxy will collide and merge with our Milky Way galaxy
- ✦Alpheratz is shared with the Great Square of Pegasus, marking one of its corners