Andromeda constellation

Andromeda represents the Ethiopian princess of Greek myth, daughter of Cepheus and Cassiopeia. After her mother boasted about her beauty, she was chained to a rock as a sacrifice to a sea monster, until Perseus came to her rescue. The constellation already appears in Ptolemy's catalogue. Its brightest star, Alpheratz, doubles as the north-eastern corner of the Great Square of Pegasus. From there a chain of stars runs via Mirach to Almach, a colourful double star that looks lovely in a small telescope. Andromeda is best known for the Andromeda Galaxy, M31, which under a dark sky can be seen with the naked eye as an oval smudge of light about 2.5 million light years away. From Central Europe, Andromeda rides high overhead on autumn evenings and stays visible for much of the year.