51 Andromedae

51 Andromedae
Location of 51 Andromedae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 01h 37m 59.56074s[1]
Declination +48° 37′ 41.5798″[1]
Apparent magnitude (V) 3.57[2]
Characteristics
Spectral type K3- III CN0.5[3]
U−B color index +1.44[2]
B−V color index +1.28[2]
Astrometry
Radial velocity (Rv)18.41[4] km/s
Proper motion (μ) RA: +61.334[1] mas/yr
Dec.: -113.100[1] mas/yr
Parallax (π)19.2489 ± 0.4077 mas[1]
Distance169 ± 4 ly
(52 ± 1 pc)
Absolute magnitude (MV)−0.04[5]
Details[6]
Mass1.75±0.15 M☉
Radius21.30±0.21 R☉
Luminosity142.1±7.6 L☉
Surface gravity (log g)2.01 cgs
Temperature4,951±64 K
Metallicity [Fe/H]0.07 dex
Age1.70±0.40 Gyr
Other designations
υ Per, 51 And, BD+47° 467, HD 9927, HIP 7607, HR 464, SAO 37375, PPM 44238[7]
Database references
SIMBADdata

51 Andromedae, abbreviated 51 And and formally named Nembus /ˈnɛmbəs/,[8] is the 5th brightest star in the northern constellation of Andromeda, very slightly dimmer than the Andromeda Galaxy also being of 4th magnitude. It is an orange K-type giant star with an apparent magnitude of +3.57 and is about 169 light-years from the Earth/solar system. It is traditionally depicted as one of the two northern, far upper ends of the mythological, chained-to-the-rocks princess, the other being binary star system Gamma Andromedae.

At an estimated age of 1.7 billion years, this is an evolved red giant star with a stellar classification of K3- III CN0.5.[3] The suffix notation indicates a mild enhancement of cyanogen absorption lines in its spectrum. This star has 1.8 times the mass of the Sun and it has expanded to 21.3 times the Sun's radius. It is radiating 142 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,951 K.[6]

  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
  2. ^ a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ a b 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.
  4. ^ Maldonado, J.; Villaver, E.; Eiroa, C. (2013). "The metallicity signature of evolved stars with planets". Astronomy & Astrophysics. 554: A84. arXiv:1303.3418. Bibcode:2013A&A...554A..84M. doi:10.1051/0004-6361/201321082. S2CID 119289111.
  5. ^ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440, S2CID 12136256.
  6. ^ a b Baines, Ellyn K.; et al. (2018), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal, 155 (1), 30, arXiv:1712.08109, Bibcode:2018AJ....155...30B, doi:10.3847/1538-3881/aa9d8b, S2CID 119427037.
  7. ^ "HD 9927". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 24 August 2018.
  8. ^ "Naming Stars". IAU.org. Retrieved 16 December 2017.