42 Librae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Libra
Right ascension 15h 34m 16.89835s[1]
Declination −10° 03′ 05.07536″[1]
Apparent magnitude (V) 4.97[2]
Characteristics
Spectral type K3-III CN2[3]
B−V color index 1.302±0.056[2]
Astrometry
Radial velocity (Rv)−21.8±2.8[2] km/s
Proper motion (μ) RA: −16.872[1] mas/yr
Dec.: −17.820[1] mas/yr
Parallax (π)8.7152 ± 0.2628 mas[1]
Distance370 ± 10 ly
(115 ± 3 pc)
Absolute magnitude (MV)−0.37[2]
Details
Radius25.9±0.4[1] R☉
Luminosity213.6±7.3[1] L☉
Surface gravity (log g)2.30[4] cgs
Temperature4,332±34[1] K
Metallicity [Fe/H]−0.03±0.06[2] dex
Other designations
42 Lib, CD−23°12458, FK5 3239, GJ 9526, HD 139663, HIP 76742, HR 5824, SAO 183686[5]
Database references
SIMBADdata

42 Librae is a single[6] star located around 370[1] light years distant from the Sun in the southern zodiac constellation of Libra.[5] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.97.[2] This object is drifting closer to the Earth with a heliocentric radial velocity of −22 km/s.[2]

This is an aging giant star with a stellar classification of K3-III CN2,[3] where the suffix notation indicates this is a strong CN star with a high overabundance of cyanogen in its spectrum. Having exhausted the supply of hydrogen at its core, this star has expanded to 26 times the Sun's radius.[1] Within the margin of error it has near-solar abundances of iron,[2] suggesting a Sun–like metallicity. The star is radiating 214[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,332 K.[1]

References

  1. ^ a b c d e f g h i j k l 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. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e f g h Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  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. ^ McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527.
  5. ^ a b "42 Lib". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-07-17.
  6. ^ 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
Categories