AE Andromedae

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AE Andromedae
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 00h 43m 02.52s
Declination +41° 49′ 12.2″
Apparent magnitude (V) 17.0-17.9[1]
Characteristics
Spectral type LBV
U−B color index -0.8=- minus;1.0[1]
B−V color index −0.1-0.1[2][1]
Variable type LBV
Astrometry
Distance ~2.5Mly ly
(~780kpc pc)
Absolute magnitude (MV) −7.0[1]
Details
Radius 25-70[2] R
Luminosity 450,000-700,000[2] L
Temperature 20,000-30,000[2] K
Other designations
AE Andromedae, AE And, HV 4476, 2MASS J00430251+4149121
Database references
SIMBAD data

AE Andromedae (AE And) is a luminous blue variable (LBV), a type of variable star. The star is one of the most luminous variables in M31, the Andromeda Galaxy.

The star was discovered by Edwin Hubble and Allan Sandage in 1953, but was not studied extensively until some 20 years later. The first spectrum was published in 1975.[3] Early in the investigations leading to the definition of LBVs, AE And was identified[1] as similar to the five Hubble-Sandage variables: Var A, Var B, Var C, and Var 2 in M33, and Var 19 in M31 (=AF Andromedae).[4]

AE And has prominent Fe II lines in its emission spectrum. It is an irregular variable, both in amplitude and period. It has an apparent magnitude of 17-18, with poorly understood longterm variations on the order of a magnitude. Its intense stellar winds have been measured on the order of 100 km/s.[5] The studied spectra were all taken near the visual minimum, at which time the star was typical of a quiescent LBV. Earlier observations showed a visually brighter star, but spectra are not available to confirm if it was in eruption at that time.

References[edit]

  1. ^ a b c d e Humphreys, R. M.; Blaha, C.; d'Odorico, S.; Gull, T. R.; Benvenuti, P. (1984). "IUE and ground-based observations of the Hubble-Sandage variables in M31 and M33". The Astrophysical Journal 278: 124. Bibcode:1984ApJ...278..124H. doi:10.1086/161774.  edit
  2. ^ a b c d Bibcode1996A&A...314..131S
  3. ^ R.M. Humphreys; "The spectra of AE Andromedae and the Hubble-Sandage variables in M31 and M33"; Astrophysical Journal, Vol. 200, p.426-429 ; September 1975; AAA014.114.322 ; doi:10.1086/153806 ; Bibcode1975ApJ...200..426H ;
  4. ^ Allan Sandage, Edwin Hubble; "The Brightest Variable Stars in Extragalactic Nebulae. I. M31 and M33"; Astrophysical Journal, vol. 118, p.353; November 1953; doi:10.1086/145764 ; Bibcode1953ApJ...118..353H
  5. ^ King, N. L.; Walterbos, R. A. M.; Braun, R.; "Discovery of Candidate Luminous Blue Variables in M31"; The Astrophysical Journal, Volume 507, Issue 1, pp.210-220; November 1998; doi:10.1086/306296 ; Bibcode1998ApJ...507..210K ;