Andromeda is a prominent constellation in the northern sky, named after Andromeda, a princess from Greek mythology. It is one of the 88 modern constellations recognized by the International Astronomical Union and is especially well known for containing the Andromeda Galaxy (M31), one of the closest large galaxies to the Milky Way.
The constellation covers an area of about 722 square degrees, making it the 19th-largest constellation in the sky. Andromeda is bordered by several other constellations, including Cassiopeia, Perseus, Pegasus, Pisces, Triangulum, and Lacerta. Its brightest star is Alpheratz (Alpha Andromedae), which has an apparent visual magnitude of about 2.1. Interestingly, Alpheratz is also associated with the constellation Pegasus and forms part of the famous Great Square of Pegasus.
One of the most notable objects in Andromeda is the Andromeda Galaxy, designated M31. Located roughly 2.5 million light-years from Earth, it is a large spiral galaxy containing hundreds of billions of stars. Under dark skies, M31 can be seen without a telescope as a faint, elongated patch of light. It is approaching the Milky Way and is expected to interact and eventually merge with our galaxy several billion years from now.
Andromeda contains many other interesting stars and deep-sky objects. Mirach (Beta Andromedae) and Almach (Gamma Andromedae) are prominent stars that help form the constellation’s distinctive shape. Almach is particularly interesting because it is a multiple-star system whose components display contrasting colors when viewed through a telescope. The constellation also contains several galaxies and star clusters, making it a rewarding region of the sky for amateur astronomers to explore.
| Star Name | Bayer Designation | Right Ascension | Declination | Visual Magnitude | Absolute Magnitude | Distance (ly) | Stellar Classification | Remarks |
|---|---|---|---|---|---|---|---|---|
| Alpheratz | α | 00h 08m 23.17s | +29° 05′ 27.0″ | 2.07 | −0.30 | 97 | B9p | Also called Sirrah; spectroscopic binary; also designated δ Pegasi. |
| Mirach | β | 01h 09m 43.80s | +35° 37′ 15.0″ | 2.07 | −1.86 | 199 | M0IIIvar | Variable star; has a known planetary or substellar companion. |
| Almach | γ¹ | 02h 03m 53.92s | +42° 19′ 47.5″ | 2.10 | −3.08 | 355 | K3IIb | Bright component of a quadruple star system. |
| δ And | δ | 00h 39m 19.60s | +30° 51′ 40.4″ | 3.27 | 0.81 | 101 | K3III | Spectroscopic binary; suspected variable. |
| Nembus | 51 | 01h 37m 59.50s | +48° 37′ 42.6″ | 3.59 | −0.04 | 174 | K3III | Multiple star system. |
| ο And | ο | 23h 01m 55.25s | +42° 19′ 33.5″ | 3.62 | −3.01 | 692 | B6pv SB | Quadruple system; γ Cas-type variable. |
| λ And | λ | 23h 37m 33.71s | +46° 27′ 33.0″ | 3.81 | 1.75 | 84 | G8III-IV | RS CVn variable star. |
| μ And | μ | 00h 56m 45.10s | +38° 29′ 57.3″ | 3.86 | 0.75 | 136 | A5V | Multiple star. |
| ζ And | ζ | 00h 47m 20.39s | +24° 16′ 02.6″ | 4.08 | 0.35 | 181 | K1II | Shimu; β Lyr/RS CVn variable. |
| Titawin | υ | 01h 36m 47.98s | +41° 24′ 23.0″ | 4.10 | 3.45 | 44 | F8V | Star with a multi-planet system. |
| κ And | κ | 23h 40m 24.44s | +44° 20′ 02.3″ | 4.15 | 0.57 | 170 | B9IVn | Triple star; has a planetary companion. |
| φ And | φ | 01h 09m 30.12s | +47° 14′ 30.6″ | 4.26 | −2.51 | 736 | B7III | Junnanmen; emission-line star. |
| ι And | ι | 23h 38m 08.18s | +43° 16′ 05.1″ | 4.29 | −1.65 | 502 | B8V | Also known as Rasalnaqa. |
| π And | π | 00h 36m 52.84s | +33° 43′ 09.7″ | 4.34 | −2.18 | 656 | B5V | Spectroscopic binary; suspected variable. |
| ε And | ε | 00h 38m 33.50s | +29° 18′ 44.5″ | 4.34 | 0.77 | 169 | G5III | Giant star. |
| η And | η | 00h 57m 12.43s | +23° 25′ 03.9″ | 4.40 | 0.04 | 243 | G8III-IV | Kui; spectroscopic binary. |
| σ And | σ | 00h 18m 19.71s | +36° 47′ 07.2″ | 4.51 | 1.33 | 141 | A2V | Suspected variable. |
| ν And | ν | 00h 49m 48.83s | +41° 04′ 44.2″ | 4.53 | −2.06 | 679 | B5V SB | Spectroscopic binary. |
| 7 And | — | 23h 12m 32.92s | +49° 24′ 21.5″ | 4.53 | 2.58 | 80 | F0V | Also known as Honores. |
| θ And | θ | 00h 17m 05.54s | +38° 40′ 54.0″ | 4.61 | 0.16 | 253 | A2V | Suspected variable. |
| 3 And | — | 23h 04m 10.83s | +50° 03′ 06.1″ | 4.64 | 0.94 | 179 | K0III | — |
| 65 And | — | 02h 25m 37.40s | +50° 16′ 43.2″ | 4.73 | −0.39 | 345 | K4III | Triple star. |
| 58 And | — | 02h 08m 29.15s | +37° 51′ 33.1″ | 4.78 | 0.86 | 198 | A5IV-V | — |
| 8 And | — | 23h 17m 44.62s | +49° 00′ 55.0″ | 4.82 | −1.69 | 655 | M2III | Suspected variable. |
| ω And | ω | 01h 27m 39.09s | +45° 24′ 25.0″ | 4.83 | 2.57 | 92 | F5IV | — |
| γ² And | γ² | 02h 03m 54.70s | +42° 19′ 51.0″ | 4.84 | −0.30 | 350 | B8V | Component of the γ And system. |
| 60 And | b | 02h 13m 13.34s | +44° 13′ 54.1″ | 4.84 | −1.32 | 556 | K4III | Suspected variable. |
| Adhil | ξ | 01h 22m 20.39s | +45° 31′ 43.5″ | 4.87 | 0.98 | 195 | K0III-IV | Also called Adhil. |
| τ And | τ | 01h 40m 34.80s | +40° 34′ 37.6″ | 4.96 | −1.64 | 681 | B8III | Suspected variable. |
| 41 H. And | υ | 01h 41m 46.52s | +42° 36′ 49.7″ | 4.96 | 4.45 | 41 | G2V | Spectroscopic binary. |
| ψ And | ψ | 23h 46m 02.04s | +46° 25′ 13.0″ | 4.97 | −3.05 | 1309 | G5Ib | Multiple star. |
| 22 And | — | 00h 10m 19.24s | +46° 04′ 20.2″ | 5.01 | −2.44 | 1006 | F2II | — |
| χ And | χ | 01h 39m 21.02s | +44° 23′ 10.1″ | 5.01 | 0.66 | 242 | G8III | — |
| 41 And | — | 01h 08m 00.72s | +43° 56′ 32.1″ | 5.04 | 1.14 | 196 | A3m | — |
| 2 And | — | 23h 02m 36.34s | +42° 45′ 28.1″ | 5.09 | −0.06 | 349 | A3Vn | Multiple star. |
| V428 And | 00h 36m 46.47s | +44° 29′ 18.6″ | 5.14 | −1.38 | 656 | K5III | Semiregular variable; possible planetary system. | |
| ρ And | ρ | 00h 21m 07.23s | +37° 58′ 07.3″ | 5.16 | 1.71 | 160 | F5III | — |
| HD 2421 | — | 00h 28m 13.59s | +44° 23′ 40.2″ | 5.18 | 0.63 | 265 | A2Vs | Spectroscopic binary. |
| 64 And | — | 02h 24m 24.89s | +50° 00′ 23.9″ | 5.19 | −0.11 | 375 | G8III | — |
| GN And | — | 00h 30m 07.34s | +29° 45′ 06.1″ | 5.20 | 1.43 | 185 | A7III | Low-amplitude δ Scuti variable. |
| 14 And | — | 23h 31m 17.20s | +39° 14′ 11.0″ | 5.22 | 0.80 | 249 | K0III | Also known as Veritate; has a planetary companion. |
| 49 And | — | 01h 30m 06.10s | +47° 00′ 26.6″ | 5.27 | 0.53 | 290 | K0III | — |
| 32 And | — | 00h 41m 07.20s | +39° 27′ 31.2″ | 5.30 | 0.18 | 344 | G8III | — |
| 4 And | — | 23h 07m 39.28s | +46° 23′ 14.3″ | 5.30 | 0.20 | 342 | K5III | Double star. |
| 6 Per | — | 02h 13m 36.02s | +51° 03′ 58.4″ | 5.31 | 1.38 | 199 | G8III:var | In the Andromeda boundary; spectroscopic binary and suspected variable. |
| 62 And | — | 02h 19m 16.85s | +47° 22′ 48.0″ | 5.31 | 0.84 | 255 | A1V | — |
| 18 And | — | 23h 39m 08.35s | +50° 28′ 18.3″ | 5.35 | −0.04 | 390 | B9V | — |
| 55 And | — | 01h 53m 17.35s | +40° 43′ 47.3″ | 5.42 | −0.67 | 540 | K1III | Double star. |
| 11 And | — | 23h 19m 29.79s | +48° 37′ 30.7″ | 5.44 | 0.43 | 328 | K0III | — |
| 36 And | — | 00h 54m 58.02s | +23° 37′ 42.4″ | 5.46 | 2.51 | 127 | K1IV | Suspected variable. |