Andromeda
The home of the Andromeda Galaxy, the farthest object visible to the naked eye. This is the tale of the princess nearly given to a monster.
Science
The scienceAndromeda holds the "Andromeda Galaxy" (M31), the farthest object visible to the naked eye. Lying about 2.5 million light-years away, this spiral galaxy is a close cousin much like our own Milky Way, appearing under dark skies as a faint smudge of light. Remarkably, it is approaching us at about 110 km per second, and in roughly 4.5 billion years it is predicted to collide and merge with the Milky Way to form a single giant elliptical galaxy. The chief star Alpheratz was once shared with Pegasus and forms one corner of the Great Square of Pegasus.
Mythology
How it became a constellationAndromeda, princess of Ethiopia, was set to be sacrificed to the sea monster Cetus because of her mother Cassiopeia's arrogance. As she awaited death chained to a seaside rock, the hero Perseus appeared before her, returning from slaying Medusa. Perseus defeated the monster, rescued her, and took her as his wife. In time, the two of them and her parents all became constellations, hung side by side across the autumn sky.
Observing Guide
how to observe🔭 How to find it
On an autumn evening, first find the "Great Square of Pegasus" high in the sky, then from its upper-left corner star (Alpheratz), two rows of two stars each stretch out diagonally — this is the body of Princess Andromeda, chained in place. Go from the corner to the second star (Mirach), then look up past two stars from there to find a hazy smudge of light: the Andromeda Galaxy.
✨ What to look for
Andromeda holds the "Andromeda Galaxy" (M31), the most distant object visible to the naked eye — this spiral galaxy about 2.5 million light-years away appears as an elongated smudge of light under dark skies. Right beside it are its satellite galaxies M32 and M110, observed together with it. At the eastern end of the constellation, Almach (the star Gamma) is a beautiful double star pairing a golden star with a blue one.
📍 Where to see it (US · Canada · UK · Australia)
From the US, Canada and UK, Andromeda climbs high near the zenith on autumn evenings (September–November); its northern stars are circumpolar from Canada and Britain, keeping it in view for much of the year, while from late spring into summer it sinks low. From Australia it appears low in the northern sky, upside down, on spring evenings, and the Andromeda Galaxy is a challenging, low-altitude target from there.