Kappa Librae

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Kappa Librae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Libra[1]
Right ascension 15h 41m 56.79858s[2]
Declination −19° 40′ 43.7745″[2]
Apparent magnitude (V) 4.72[3]
Characteristics
Spectral type K5 III[4]
U−B color index +1.94[3]
B−V color index +1.58[3]
Astrometry
Radial velocity (Rv)−4.5±1.5[5] km/s
Proper motion (μ) RA: −32.06[2] mas/yr
Dec.: −103.15[2] mas/yr
Parallax (π)10.57±1.40 mas[2]
Distanceapprox. 310 ly
(approx. 90 pc)
Absolute magnitude (MV)−0.62[1]
Details
Mass1.6[6] M☉
Radius38[7] R☉
Luminosity388[8] L☉
Surface gravity (log g)1.35[6] cgs
Temperature3,875[7] K
Metallicity [Fe/H]−0.39[6] dex
Other designations
κ Lib, 43 Lib, BD−19°4188, FK5 1413, HD 139997, HIP 76880, HR 5838, SAO 159442[9]
Database references
SIMBADdata

Kappa Librae is a star system in the zodiac constellation of Libra. Its name is a Bayer designation that is Latinized from κ Librae, and abbreviated Kappa Lib or κ Lib. Its apparent visual magnitude is 4.72,[3] so it can be seen with the naked eye. The annual parallax shift of 10.57 mas[2] indicates it is roughly 310 light years away. It is positioned 0.02 degrees south of the ecliptic.

The star shows acceleration components in its proper motion, indicating with high probability that it is an astrometric binary.[10] The visible component is an evolved K-type giant star with a stellar classification of K5 III.[4] It is a suspected variable star with a brightness that ranges between 4.70 and 4.75.[11] Kappa Librae is 38 times larger than the Sun,[7] and is radating 388 times the solar luminosity[8] from its outer atmosphere at an effective temperature of 3,875 K.[7]

In Chinese astronomy, Kappa Librae is called 日, Pinyin: Rì, meaning Sun, because this star is marking itself and stand alone in Sun asterism, Room mansion (see : Chinese constellation).[12]

References

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  1. ^ a b 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. XHIP record for this object at VizieR.
  2. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  3. ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  4. ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
  5. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  6. ^ a b c Kaltenegger, L.; Faherty, J. K. (2021), "Past, present and future stars that can see Earth as a transiting exoplanet", Nature, 594 (7864): 505–507, arXiv:2107.07936, Bibcode:2021Natur.594..505K, doi:10.1038/s41586-021-03596-y, PMID 34163055
  7. ^ a b c d McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01), "Fundamental parameters and infrared excesses of Tycho-Gaia stars", Monthly Notices of the Royal Astronomical Society, 471: 770–791, arXiv:1706.02208, Bibcode:2017MNRAS.471..770M, doi:10.1093/mnras/stx1433, ISSN 0035-8711. Kappa Librae's database entry at VizieR.
  8. ^ a b 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.
  9. ^ "kap Lib". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-30.{{cite web}}: CS1 maint: postscript (link)
  10. ^ Makarov, V. V.; Kaplan, G. H. (May 2005), "Statistical Constraints for Astrometric Binaries with Nonlinear Motion" (PDF), The Astronomical Journal, 129 (5): 2420–2427, Bibcode:2005AJ....129.2420M, doi:10.1086/429590, archived from the original on September 24, 2017.
  11. ^ Samus, N. N.; Durlevich, O. V.; et al. (2004), "Combined General Catalogue of Variable Stars (GCVS4.2)", Vizier Online Data Catalog, Bibcode:2004yCat.2250....0S.
  12. ^ Ian Ridpath's Startales - Libra the Scales