Andromeda constellation
Andromeda (the Chained Princess) is a constellation in the northern sky, best seen in the evening in November. Its brightest star is Alpheratz (magnitude 2.06). Andromeda covers 722 square degrees and is the 19th-largest of the 88 constellations.
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How to find Andromeda, step by step
A chain of stars from the Great Square.
- On autumn evenings find the Great Square of Pegasus.
- Its northeast corner, Alpheratz, is the head of Andromeda.
- From Alpheratz two lines of stars fan out to the east; the brighter one runs through Mirach to Almach. Two stars up from Mirach lies the Andromeda Galaxy (see that guide).
Detailed star map of Andromeda
Facts
| Latin name | Andromeda (genitive: Andromedae) |
|---|---|
| Abbreviation | And |
| Meaning | the Chained Princess |
| Area | 722 square degrees (19th of 88) |
| Location | right ascension 0.7 h, declination +41° |
| Visible from | latitudes 90° N to 37° S (whole constellation) |
| Best month | November (at about 9 pm) |
| Brightest star | Alpheratz |
| Stars brighter than magnitude 6 | 83 |
| Named stars (IAU) | 7 |
| Messier objects | M31, M32, M110 |
| Neighbors | Cassiopeia, Lacerta, Pegasus, Perseus, Pisces, Triangulum |
How to find Andromeda
From 40° N (the USA, southern Europe, Japan) look north in November evenings: at about 9 pm Andromeda stands highest, around 89° above the northern horizon. From 35° S (Australia, South Africa, Argentina) it is highest in the north, about 14° above the horizon. The months before and after (October and December) are also good: then it is up a couple of hours earlier or later.
Andromeda borders Cassiopeia, Lacerta, Pegasus, Perseus, Pisces and Triangulum.
Asterisms with stars in Andromeda: Great Square of Pegasus.
Stars of Andromeda
Andromeda has 83 stars brighter than magnitude 6, the limit of the naked eye under a dark sky. These are the brightest:
| Star | Designation | Magnitude | Type | Distance |
|---|---|---|---|---|
| Alpheratz | α Andromedae | 2.06 | B8IVpMnHg | 97 ly |
| Mirach | β Andromedae | 2.06 | M0+IIIa | 199 ly |
| Almach | γ1 Andromedae | 2.26 | K3-IIb | 350 ly |
| — | δ Andromedae | 3.27 | K3III | — |
| Nembus | 51 Andromedae | 3.57 | K3-III | 176 ly |
| — | ο Andromedae | 3.62 | B6IIIpe+A2p | — |
| — | λ Andromedae | 3.82 | G8III-IV | — |
| — | μ Andromedae | 3.87 | A5V | — |
| — | ζ Andromedae | 4.06 | K1IIe | — |
| Titawin | υ Andromedae | 4.09 | F8V | 44 ly |
| — | κ Andromedae | 4.14 | B9IVn | — |
| — | φ Andromedae | 4.25 | B7Ve | — |
Deep-sky objects in Andromeda
Andromeda contains 3 objects from Charles Messier's catalog:
- Andromeda Galaxy (M31): spiral galaxy, 3.4 mag
- Messier 32 (M32): elliptical galaxy, 8.1 mag
- Messier 110 (M110): elliptical galaxy, 8.1 mag
Printable Andromeda map and outline
A black and white version for printing and a plain outline of the Andromeda figure, useful for school projects, worksheets and learning to recognize the shape.
History
Andromeda is one of the 48 constellations listed by Ptolemy in the Almagest (2nd century AD). Its official boundary was drawn by Eugène Delporte for the International Astronomical Union in 1930.
Questions about Andromeda
What is the brightest star in Andromeda?
Alpheratz, at magnitude 2.06, about 97 light-years away.
When can you see Andromeda?
Andromeda is best seen in the evening in November. The whole constellation is visible from latitudes between 90° N and 37° S.
How many stars are in Andromeda?
83 stars in Andromeda are brighter than magnitude 6 and can be seen with the naked eye under a dark sky; 7 of them have official IAU names.
What does Andromeda mean?
Andromeda means “the Chained Princess” in Latin. Its abbreviation is And and the genitive, used in star names such as α Andromedae, is Andromedae.
