Astronomy:37 Librae

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Short description: Star in the constellation Libra
37 Librae
Observation data
Equinox J2000.0]] (ICRS)
Constellation Libra
Right ascension  15h 34m 10.70209s[1]
Declination −10° 03′ 52.3063″[1]
Apparent magnitude (V) 4.61[2]
Characteristics
Evolutionary stage subgiant[3]
Spectral type K1III–IV[4]
B−V color index 1.00±0.03[2]
Astrometry
Radial velocity (Rv)+49.25±0.08[5] km/s
Proper motion (μ) RA: +307.63[1] mas/yr
Dec.: −234.51[1] mas/yr
Parallax (π)34.57 ± 0.22[1] mas
Distance94.3 ± 0.6 ly
(28.9 ± 0.2 pc)
Absolute magnitude (MV)2.30[2]
Details[5]
Mass1.38±0.10 M
Radius5.09±0.19 R
Luminosity13.5+1.6
−1.5
 L
Surface gravity (log g)3.19±0.06 cgs
Temperature4,836±22 K
Metallicity [Fe/H]0.02±0.04 dex
Rotational velocity (v sin i)2.02±0.33 km/s
Age3.39±0.80 Gyr
Other designations
37 Lib, BD−09°4171, FK5 1409, GC 20914, HD 138716, HIP 76219, HR 5777, SAO 140609[6]
Database references
SIMBADdata

37 Librae is a single[7] star in the southern zodiac constellation of Libra. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.61.[2] The star is located 94 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +49 km/s.[5]

This is an evolving subgiant star[3] with a stellar classification of K1 III–IV,[4] where the luminosity class indicates the spectrum displays blended traits of a subgiant and a giant star. It is an estimated 3.4 billion years old with 1.4 times the mass of the Sun. Having the supply of hydrogen at its core all but exhausted, the star is starting to expand; currently it has five times the girth of the Sun. It is radiating 13.5 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,836 K.[5]

References

  1. 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Snowden, Michael S.; Young, Arthur (March 2005), "Radial Velocities of Late-Type Field Subgiant Stars", The Astrophysical Journal Supplement Series 157 (1): 126–137, doi:10.1086/423711, Bibcode2005ApJS..157..126S. 
  4. 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K. 
  5. 5.0 5.1 5.2 5.3 Jofré, E. et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics 574: A50, doi:10.1051/0004-6361/201424474, A50, Bibcode2015A&A...574A..50J. 
  6. "37 Lib". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=37+Lib. 
  7. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E.