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David

Darling

Andromeda

Andromeda constellation

Andromeda. © 2005 Torsten Bronger.


Andromeda (abbreviation And) is a large, prominent northern constellation, to the south of Cassiopeia, between Perseus and Pegasus.

 

In mythology, Andromeda was chained to a rock to be sacrificed to Cetus (the Whale) as a punishment to her mother, Cassiopeia, who had boasted that she was more beautiful than the daughters of Neptune.

 

Andromeda's three brightest stars lie along an arc that stretches to the northeast of the Square of Pegasus, of which Alpheratz (Alpha Andromedae) forms a corner. Alpheratz and Mirach, the two brightest stars, have identical magnitudes, which is a coincidence found in no other constellation. Near to third-ranked Almaak is the most outstanding feature of Andromeda – our nearest neighboring major galaxy, the Andromeda Galaxy.

 

See below for details of the constellation's brightest stars and interesting deep sky objects.

 


S Andromedae

S Andromedae, also known as SN 1885 (Supernova 1885), is the only supernova seen to date in the Andromeda Galaxy and the first supernova observed beyond the galaxy in which we live, Milky Way Galaxy. S Andromedae (a variable star designation) was discovered on Aug. 19, 1885, by the Irish amateur astronomer Isaac Ward in Belfast, and independently the following day by Ernst Hartwig (1851–1923) at Dorpat Observatory in Estonia; Hartwig was the first to realize its significance.

 

S Andromedae reached magnitude 6 between Aug. 17 and 20, and had faded to magnitude 16 by February 1890. In 1988, R. A. Fesen and colleagues using the 4-meter Mayall telescope at Kitt Peak discovered the remnant of the explosion; further observations were made with the Hubble Space Telescope in 1995.

 


Stars in Andromeda brighter than magnitude 4.0
Star Visual mag. Abs. mag. Spectral type Distance (lt-yr) R.A. (h m s) Dec. (° ' ")
Alpha (Alpheratz) 2.07 -0.30 B8IVpMnHg 97 00 08 23 +29 05 26
Beta (Mirach) 2.07 -1.87 M0IIa 199 01 09 44 +35 37 14
Gamma (Almaak) 2.10 -3.09 K3IIb+A0V 355 02 03 54 +42 19 47
Delta 3.27 0.81 K3III 101 00 39 20 +30 51 40
51 3.59 -0.05 K3III 174 01 38 00 +48 37 42
Omicron 3.6v 1.33 B6IIIpe+A2p 141 23 01 55 +42 19 34
Lambda 3.82v 1.75 G8III-Iv 84 23 37 34 +46 27 30
Mu 3.86 0.75 A5V 136 00 56 45 +38 29 58
Upsilon 4.63 3.96 F8V 43.9 01 36 48 +41 24 20
Gliese 67 4.96 4.45 G2V 41.4 01 41 47 +42 36 48
Groombridge 34 (A) 8.09 10.33 M1.5V 11.62 00 18 23 +44 01 22
Ross 248 12.29 14.79 M5.5V 10.32 23 41 55 +44 10 30

 


Other objects of interest
Name Type of object Notes
R And star Mira variable. Mag. range 5.8 to 14.9; mean period 409 days; R.A. 02h 24.0m, Dec. +38° 35'
Z And star The prototype Z Andromedae star
LL And star See brown dwarf.
Andromeda Galaxy galaxy M31 (NGC 224). See main entry
M32 (NGC 221) galaxy Bright satellite of the Andromeda Galaxy.
M110 (NGC 205) galaxy Bright satellite of the Andromeda Galaxy.
Cassiopeia Dwarf galaxy Faint satellite of the Andromeda Galaxy.
Pegasus Dwarf galaxy Faint satellite of the Andromeda Galaxy.
NGC 404 galaxy Mirach's Ghost. Lies very close to Mirach in our line of sight.
NGC 891 galaxy One of best examples of an edge-on spiral. R.A. 02h 19m, Dec. +42° 7'
NGC 752 open cluster Fine object, 5° S. of Almaak, best viewed with binoculars as its 70-80 stars are widely scattered. R.A. 01h 57.8m, Dec. +37° 41'
Blue Snowball Nebula (NGC 7662) planetary nebula See main entry


Constellations
Andromeda | Antlia | Apus | Aquarius | Aquila | Ara | Aries | Auriga | Bootes | Caelum | Camelopardalis | Cancer | Canes Venatici | Canis Major | Canis Minor | Capricornus | Carina | Cassiopeia | Centaurus | Cepheus | Cetus | Chamaeleon | Circinus | Columba | Coma Berenices | Corona Austrina | Corona Borealis | Corvus | Crater | Crux | Cygnus | Delphinus | Dorado | Draco | Equuleus | Eridanus | Fornax | Gemini | Grus | Hercules | Horologium | Hydra | Hydrus | Indus | Lacerta | Leo | Leo Minor | Lepus | Libra | Lupus | Lynx | Lyra | Mensa | Microscopium | Monoceros | Musca | Norma | Octans | Ophiuchus | Orion | Pavo | Pegasus | Perseus | Phoenix | Pictor | Pisces | Piscis Austrinus | Puppis | Pyxis | Reticulum | Sagitta | Sagittarius | Scorpius | Sculptor | Scutum | Serpens | Sextans | Taurus | Telescopium | Triangulum | Triangulum Australe | Tucana | Ursa Major | Ursa Minor | Vela | Virgo | Volans | Vulpecula