How did the Andromeda Constellation Get its Name?


The Andromeda constellation is named after the mythical Greek princess Andromeda. According to the myth, Andromeda was the daughter of Queen Cassiopeia and King Cepheus of Ethiopia. The queen boasted that her daughter was more beautiful than the sea nymphs, which angered the god of the sea, Poseidon. As punishment, Poseidon sent a sea monster, Cetus, to attack the kingdom.

The Myth of Andromeda

In the myth, Andromeda was chained to a rock as an offering to the sea monster Cetus. However, Perseus, the son of Zeus and a hero in Greek mythology, came to her rescue. He defeated the monster using Medusa’s head, which turned Cetus to stone.

Perseus fell in love with Andromeda and married her. The couple then traveled the world together and had seven sons and two daughters.

The Naming of the Andromeda Constellation

The Andromeda constellation was named by the Greek astronomer Ptolemy in the 2nd century AD. He included it in his famous work, the Almagest, along with 47 other constellations.

The constellation can be seen in the northern hemisphere during autumn and winter. It is known for its bright star, Alpheratz, which marks Andromeda’s head. Andromeda’s body and legs are marked by a chain of stars that curves around the constellation Cassiopeia.

Andromeda’s Place in the Night Sky

The Andromeda constellation is home to the Andromeda Galaxy, also known as Messier 31. The galaxy is one of the closest to Earth, at a distance of about 2.5 million light-years away.

The Andromeda Galaxy is also the largest galaxy in the Local Group, which includes the Milky Way and other nearby galaxies. It is visible to the naked eye and has been observed by astronomers since ancient times.


The Andromeda constellation is named after the mythological princess Andromeda, who was saved by the hero Perseus from the sea monster Cetus. The constellation is known for its bright star, Alpheratz, and is home to the Andromeda Galaxy, one of the closest and largest galaxies to Earth. The mythology and astronomy behind the Andromeda constellation make it a fascinating object to study and observe in the night sky.