47 Andromedae

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47 Andromedae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Andromeda
Right ascension  01h 23m 40.61627s[1]
Declination +37° 42′ 53.7861″[1]
Apparent magnitude (V) 5.60 (6.33 + 6.38)[2]
Spectral type A1m[3]
B−V color index 0.276[2]
Radial velocity (Rv)+13.3±0.9[4] km/s
Proper motion (μ) RA: +82.07[1] mas/yr
Dec.: −20.46[1] mas/yr
Parallax (π)15.66 ± 0.30[1] mas
Distance208 ± 4 ly
(64 ± 1 pc)
Absolute magnitude (MV)2.30±0.06/2.35±0.06[2]
Period (P)35.36815±0.00015 d
Eccentricity (e)0.64781±0.00090
Periastron epoch (T)2,454,293.2187 ± 0.0056 HJD
Semi-amplitude (K1)
39.216±0.079 km/s
Semi-amplitude (K2)
40.47±0.073 km/s
47 And A
Radius1.9±0.1[2] R
Luminosity9.0±0.5[2] L
Age710[5] Myr
47 And B
Radius1.8±0.1[2] R
Luminosity8.6±0.5[2] L
Other designations
47 And, BD+36° 237, FK5 2093, HD 8374, HIP 6514, HR 395, SAO 54655[6]
Database references

47 Andromedae is a binary star[2] system in the northern constellation of Andromeda. The designation is from the star catalogue of John Flamsteed, first published in 1712; the system has a combined apparent visual magnitude of 5.60,[2] which is just bright enough to be faintly visible to the naked eye under good seeing conditions. The distance to this system, as determined from an annual parallax shift of 15.66 mas,[1] is about 208 light years. It is moving away from the Sun with a heliocentric radial velocity of +13.3 km/s.[4]

The binary nature of this system was discovered by J. S. Plaskett and R. K. Young in 1919. It is a double-lined spectroscopic binary with an orbital period of 35.4 days and an eccentricity of 0.65. The components appear to be nearly identical Am stars, with a magnitude difference of 0.05.[2] The combined stellar classification is A1m.[3]


  1. ^ a b c d e f 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.
  2. ^ a b c d e f g h i j k Fekel, Francis C.; et al. (September 2011), "New Precision Orbits of Bright Double-lined Spectroscopic Binaries. VII. 47 Andromedae, 38 Cassiopeiae, and HR 8467", The Astronomical Journal, 142 (3): 13, Bibcode:2011AJ....142...69F, doi:10.1088/0004-6256/142/3/69, 69
  3. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
  4. ^ a b Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065.
  5. ^ De Rosa, R. J.; et al. (2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216, arXiv:1311.7141, Bibcode:2014MNRAS.437.1216D, doi:10.1093/mnras/stt1932.
  6. ^ "47 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-22.