Andromeda
A long, straggling constellation of faint stars that holds the most famous object in the northern sky: the Andromeda Galaxy, M31. It shares a corner star with Pegasus, so the two constellations are often traced together.
Star chart · schematic positions
Drag to pan · dashed rings mark deep-sky objects · east is left
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Tap any labelled star in the chart to read its name, magnitude and spectral type.
Why it matters
Andromeda contains M31, the nearest large galaxy and the most distant object visible to the unaided eye. The constellation sits away from the Milky Way's plane, giving a clear view out of our own galaxy — which is why its extragalactic treasures are so easy to see.
How to find it tonight
- 1Find the Great Square of Pegasus in autumn; Alpheratz is its north-eastern corner and belongs to Andromeda.
- 2Follow the chain of stars eastward from Alpheratz through δ and Mirach.
- 3From Mirach, jump north-west to the fainter star μ, then continue the same distance to M31.
- 4Under a dark sky M31 is a smudge about the width of the full Moon; binoculars show its bright core and two companions.
Brightest stars on the chart
Alpheratz (α Andromedae) · Mirach (β Andromedae) · Almach (γ Andromedae) · Delta Andromedae (δ Andromedae)
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Figures are rounded averages from NASA, ESA and IAU reference data. Star positions on charts are schematic and approximate.