42 Librae
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]
| 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[1] mas |
| Distance | 370 ± 10 ly (115 ± 3 pc) |
| Absolute magnitude (MV) | −0.37[2] |
| Details | |
| Radius | 25.9±0.4[1] R☉ |
| Luminosity | 213.6±7.3[1] L☉ |
| Surface gravity (log g) | 2.30[4] cgs |
| Temperature | 4,332±34[1] K |
| Metallicity [Fe/H] | −0.03±0.06[2] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K3-III CN2,[3] where the suffix notation indicates a high overabundance of CN 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
- 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.
- 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.
- 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.
- 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.
- "42 Lib". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-07-17.
- 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.