Gamma Andromedae

Not to be confused with Y Andromedae.
"Alamak" redirects here. For the Singaporean comedian, see Henry Thia.
γ1 Andromedae
(γ Andromedae A)
Location of γ Andromedae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Andromeda
Right ascension 02h 03m 53.95229s[1]
Declination +42° 19′ 47.0223″[1]
Apparent magnitude (V) 2.27[2]
Characteristics
Evolutionary stage Candidate post-AGB[3]
Spectral type K2+IIb[4]
U−B color index +1.58[2]
B−V color index +1.37[2]
R−I color index +0.68[2]
Astrometry
Radial velocity (Rv)−11.7±0.9[5] km/s
Proper motion (μ) RA: 42.32[1] mas/yr
Dec.: −49.30[1] mas/yr
Parallax (π)8.30 ± 1.04 mas[1]
Distanceapprox. 390 ly
(approx. 120 pc)
Absolute magnitude (MV)-3.09
Details
Radius98.5[6] R☉
Luminosity2987±412[6] L☉
Surface gravity (log g)1.03[7] cgs
Temperature4,248[7] K
Metallicity [Fe/H]−0.06[3] dex
Rotational velocity (v sin i)< 17[2] km/s
Orbit[8]
Primaryγ1 Andromedae
Companionγ2 Andromedae
Period (P)4,748 yr
Other designations
Almach, Almaach, Almak, Almaak, Alamak, γ1 And, Gamma1 Andromedae, Gamma1 And, γ Andromedae A, γ And A, Gamma Andromedae A, Gamma And A, 57 Andromedae A, 57 And A, BD+41 395, FK5 73, GC 2477, HD 12533, HIP 9640, HR 603, SAO 37734, PPM 44721, ADS 1630 A, CCDM J02039+4220A, WDS 02039+4220A[2][9][10]
Database references
SIMBADdata

Gamma Andromedae, Latinized from γ Andromedae, is the third-brightest point of light in the northern constellation of Andromeda. It is a multiple star system approximately 390 light-years from Earth. The system is drifting closer to the Sun with a radial velocity in the range of −12 to −14 km/s.[5]

  1. ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d e f Hoffleit, Dorrit; Jaschek, Carlos (1991). The Bright star catalogue. Bibcode:1991bsc..book.....H. "database entry". CDS. Retrieved 2019-11-19.
  3. ^ a b Rao, S. Sumangala; Giridhar, Sunetra; Lambert, David L. (January 2012). "Chemical composition of a sample of candidate post-asymptotic giant branch stars". Monthly Notices of the Royal Astronomical Society. 419 (2): 1254–1270. Bibcode:2012MNRAS.419.1254R. doi:10.1111/j.1365-2966.2011.19780.x.
  4. ^ Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373, S2CID 123149047.
  5. ^ a b Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication. Bibcode:1953GCRV..C......0W.
  6. ^ a b McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01), "Fundamental parameters and infrared excesses of Tycho-Gaia stars", Monthly Notices of the Royal Astronomical Society, 471: 770–791, arXiv:1706.02208, doi:10.1093/mnras/stx1433, ISSN 0035-8711 Gamma Andromedae's database entry at VizieR.
  7. ^ a b Luck, R. Earle (2014-06-01). "Parameters and Abundances in Luminous Stars". The Astronomical Journal. 147 (6): 137. Bibcode:2014AJ....147..137L. doi:10.1088/0004-6256/147/6/137. ISSN 0004-6256.
  8. ^ Tokovinin, A. A. "HIP 9640". Multiple Star Catalogue. Archived from the original on 2020-10-02. Retrieved 2019-11-19.
  9. ^ "* gam01 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved August 19, 2008.
  10. ^ Cite error: The named reference wds0 was invoked but never defined (see the help page).