Beta Leporis
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Lepus |
Right ascension | 05h 28m 14.72316s[1] |
Declination | −20° 45′ 33.9878″[1] |
Apparent magnitude (V) | 2.813[2] |
Characteristics | |
Spectral type | G5 II[3] |
U−B color index | +0.47[4] |
B−V color index | +0.808[2] |
R−I color index | +0.44[5] |
Astrometry | |
Radial velocity (Rv) | −13.6 ± 0.9[6] km/s |
Proper motion (μ) | RA: −5.02[1] mas/yr Dec.: −85.92[1] mas/yr |
Parallax (π) | 20.34 ± 0.18 mas[1] |
Distance | 160 ± 1 ly (49.2 ± 0.4 pc)[1] |
Absolute magnitude (MV) | −0.65[7] |
Details | |
Mass | 2.948±0.031[2] M☉ |
Radius | 12.573±0.153[2] R☉ |
Luminosity | 171[8] L☉ |
Surface gravity (log g) | 2.88[2] cgs |
Temperature | 5,398[2] K |
Metallicity [Fe/H] | −0.08±0.02[2] dex |
Rotational velocity (v sin i) | 11[9] km/s |
Age | 391±11[2] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Beta Leporis (β Leporis, abbreviated Beta Lep, β Lep), formally named Nihal /ˈnaɪ.æl/,[10][11] is the second brightest star in the constellation of Lepus.[12]
Nomenclature
[edit]Beta Leporis is the star's Bayer designation. It is also known by the traditional named Nihal, Arabic for "quenching their thirst". The occasional spelling Nibal appears to be due to a misreading.[13] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[14] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[15] included a table of the first two batches of names approved by the WGSN; which included Nihal for this star.
In Chinese, 廁 (Cè), meaning Toilet, refers to an asterism consisting of β Leporis, α Leporis, γ Leporis and δ Leporis.[16] Consequently, the Chinese name for β Leporis itself is 廁二 (Cè èr), "the Second Star of Toilet".[17]
Properties
[edit]Based on parallax measurements from the Hipparcos astrometry satellite,[18] this star is located about 160 light-years (49 parsecs) from the Earth. It has an apparent visual magnitude of 2.81[2] and a stellar classification of G5 II.[3] The mass of this star is 3 times the mass of the Sun and it is about 390 million years old,[2] which is the sufficient time for a star this massive to consume the hydrogen at its core and evolve away from the main sequence, becoming a G-type bright giant.[3] Currently, it has expanded to 12.6 times the Sun's size[2] and is emitting 171 times its luminosity.[8]
This is a double star system and may be a binary, whereby the second star has a brightness of 7.34 mag.[19] Using adaptive optics on the AEOS telescope at Haleakala Observatory, the pair was found to be separated by an angle of 2.58 arcseconds at a position angle of 1.4°.[20] Component B has been observed to fluctuate in brightness and is catalogued as suspected variable star NSV 2008.[21]
References
[edit]- ^ a b c d e f van Leeuwen, F. (November 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.
- ^ a b c d e f g h i j k Gomes da Silva, J.; Santos, N. C.; Adibekyan, V.; Sousa, S. G.; Campante, T. L.; Figueira, P.; Bossini, D.; Delgado-Mena, E.; Monteiro, M. J. P. F. G.; de Laverny, P.; Recio-Blanco, A.; Lovis, C. (2021-02-01). "Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample. I. A catalogue of homogeneous chromospheric activity". Astronomy and Astrophysics. 646: A77. arXiv:2012.10199. Bibcode:2021A&A...646A..77G. doi:10.1051/0004-6361/202039765. ISSN 0004-6361. Beta Leporis' database entry at VizieR.
- ^ a b c d "CCDM J05283-2046AB -- Double or multiple star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-27
- ^ 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.
- ^ HR 1829, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line November 18, 2008.
- ^ Evans, D. S. (1967), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 held at the University of Toronto 20-24 June, 1966, vol. 30, Academic Press, London, p. 57, Bibcode:1967IAUS...30...57E
- ^ 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 Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M
- ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago. 239 (1): 1. Bibcode:1970CoAsi.239....1B.
- ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
- ^ "IAU Catalog of Star Names". Retrieved 28 July 2016.
- ^ Kaler, James B., "Nihal", Stars, archived from the original on 2008-12-10, retrieved 2008-11-18
- ^ Allen, Richard Hinckley (1899), Star-names and Their Meanings, New York: G. E. Steichert, pp. 265, 269
- ^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
- ^ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Retrieved 28 July 2016.
- ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2008-10-25 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ^ Perryman, Michael (2010), The Making of History's Greatest Star Map, Astronomers' Universe, Heidelberg: Springer-Verlag, Bibcode:2010mhgs.book.....P, doi:10.1007/978-3-642-11602-5, ISBN 978-3-642-11601-8
- ^ "Nihal - β Leporis (beta Leporis) - Star in Lepus | TheSkyLive.com". theskylive.com. Retrieved 2023-03-28.
- ^ Roberts, Lewis C. Jr. (May 2011), "Astrometric and photometric measurements of binary stars with adaptive optics: observations from 2002", Monthly Notices of the Royal Astronomical Society, 413 (2): 1200–1205, arXiv:1012.3383, Bibcode:2011MNRAS.413.1200R, doi:10.1111/j.1365-2966.2011.18205.x, S2CID 118398949
- ^ "NSV 2008, database entry", New Catalogue of Suspected Variable Stars, the improved version, Moscow, Russia.: Sternberg Astronomical Institute, retrieved 2008-11-18