42 Librae

42 Librae
Observation data Epoch J2000.0 Equinox J2000.0
Constellation	Libra
Right ascension	15^h 34^m 16.89835^s^[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 (R_v)	−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]
Distance	370 ± 10 ly (115 ± 3 pc)
Absolute magnitude (M_V)	−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
42 Lib, CD−23°12458, FK5 3239, GJ 9526, HD 139663, HIP 76742, HR 5824, SAO 183686^[5]
Database references
SIMBAD	data

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

^ ^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.
^ ^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.
^ ^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.
^ 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.
^ ^a ^b "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, S2CID 14878976.

Bayer	α¹ α² (Zubenelgenubi) β (Zubeneschamali) γ (Zubenelhakrabi) δ (Zuben Elakribi) ε ζ¹ ζ² ζ³ ζ⁴ η θ ι¹ ι² κ λ μ ν ξ¹ ξ² ο σ (Brachium) τ υ
Flamsteed	2 3 4 5 10 11 12 16 17 18 22 23 26 28 30 33 36 37 41 42 47 48 49 50 30 Ser
Variable	HO KU KX
HR	5455
HD	133112 133131 134439 134440 139139 140283 141569 141937
Other	2M1510 2MASS 1507−1627 Gliese 555 HE 1523-0901 WASP-57 WISE 1541−2250

Exoplanets	23 Librae b c γ Librae b c Gliese 581 b c d (unconfirmed) e g (unconfirmed) WASP-189 b

Star clusters	NGC 5897

NGC	5728 5792 5793 5861 5890 5917
Other	AP Librae IC 1059