The traditional name Chara was originally applied to the "southern dog", but it later became used specifically to refer to Beta Canum Venaticorum. Chara (χαρά) means 'joy' in Greek.[14] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[15] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[16] included a table of the first two batches of names approved by the WGSN; which included Chara for this star.
Beta CVn has a stellar classification of G0 V, and so is a G-type main-sequence star. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[19] The spectrum of this star shows a very weak emission line of singly ionized calcium (Ca II) from the chromosphere, making it a useful reference star for a reference spectrum to compare with other stars in a similar spectral category.[20] (The Ca-II emission lines are readily accessible and can be used to measure the level of activity in a star's chromosphere.)
Beta CVn is considered to be slightly metal-poor,[9] which means it has a somewhat lower portion of elements heavier than helium when compared to the Sun. In terms of mass, age and evolutionary status, however, this star is very similar to the Sun.[21] As a result, it has been called a solar analog. It is about 3% less massive than the Sun,[2] with a radius 3% larger than the Sun's and 25% greater luminosity.[8][9]
The components of this star's space velocity are (U, V, W) = (–25, 0, +2) km/s.[21] In the past it was suggested that it may be a spectroscopic binary. However, further analysis of the data does not seem to bear that out.[22] In addition, a 2005 search for a brown dwarf in orbit around this star failed to discover any such companion, at least down to the sensitivity limit of the instrument used.[23]
Habitability
edit
In 2006, astronomer Margaret Turnbull labeled Beta CVn as the top stellar system candidate to search for extraterrestrial life forms.[24] Because of its solar-type properties, astrobiologists have listed it among the most astrobiologically interesting stars within 10 parsecs of the Sun.[21] However, as of 2009, this star is not known to host planets.[2]
^ abcdefBrown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
^ abcvan Belle, Gerard T.; von Braun, Kaspar (April 2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal. 694 (2): 1085–1098. arXiv:0901.1206. Bibcode:2009ApJ...694.1085V. doi:10.1088/0004-637X/694/2/1085. S2CID 18370219.
^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.
^Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Washington: Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
^ abHolmberg, J.; Nordström, B.; Andersen, J. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics. 501 (3): 941–947. arXiv:0811.3982. Bibcode:2009A&A...501..941H. doi:10.1051/0004-6361/200811191. S2CID 118577511.
^ abLlorente de Andrés, F.; Chavero, C.; de la Reza, R.; Roca-Fàbrega, S.; Cifuentes, C. (October 2021). "The evolution of lithium in FGK dwarf stars. The lithium-rotation connection and the Li desert". Astronomy and Astrophysics. 654: A137. arXiv:2108.05852. Bibcode:2021A&A...654A.137L. doi:10.1051/0004-6361/202141339. ISSN 0004-6361.
^ abBaines, Ellyn K.; Armstrong, J. Thomas; Schmitt, Henrique R.; Zavala, R. T.; Benson, James A.; Hutter, Donald J.; Tycner, Christopher; van Belle, Gerard T. (2017). "Fundamental parameters of 87 stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 155 (1): 16. arXiv:1712.08109. Bibcode:2018AJ....155...30B. doi:10.3847/1538-3881/aa9d8b. S2CID 119427037.
^ abcdefSoubiran, C.; Creevey, O. L.; Lagarde, N.; Brouillet, N.; Jofré, P.; Casamiquela, L.; Heiter, U.; Aguilera-Gómez, C.; Vitali, S.; Worley, C.; de Brito Silva, D. (2024-02-01). "Gaia FGK benchmark stars: Fundamental Teff and log g of the third version". Astronomy and Astrophysics. 682: A145. arXiv:2310.11302. Bibcode:2024A&A...682A.145S. doi:10.1051/0004-6361/202347136. ISSN 0004-6361. Beta Canum Venaticorum's database entry at VizieR.
^Herrero, E.; et al. (January 2012). "Optimizing exoplanet transit searches around low-mass stars with inclination constraints". Astronomy & Astrophysics. 537: A147. arXiv:1110.5840. Bibcode:2012A&A...537A.147H. doi:10.1051/0004-6361/201117809. S2CID 119299265.
^"bet CVn -- Spectroscopic binary". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-07-04.
^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, Jim. "Beta Canum Venaticorum". Stars. University of Illinois. Archived from the original on 2007-02-20. Retrieved 2006-12-06.
^"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 2009-09-29 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
^Garrison, R. F. (December 1993). "Anchor Points for the MK System of Spectral Classification". Bulletin of the American Astronomical Society. 25: 1319. Bibcode:1993AAS...183.1710G. Archived from the original on 2019-06-25. Retrieved 2012-02-04.
^Herbig, G. H. (1985). "Chromospheric H-alpha emission in F8-G3 dwarfs, and its connection with the T Tauri stars". Astrophysical Journal. 289 (1): 269–278. Bibcode:1985ApJ...289..269H. doi:10.1086/162887.
^ abcde Mello, G. P.; del Peloso, E. F.; Ghezzi, L. (2006). "Astrobiologically Interesting Stars Within 10 Parsecs of the Sun". Astrobiology. 6 (2): 308–331. arXiv:astro-ph/0511180. Bibcode:2006AsBio...6..308P. doi:10.1089/ast.2006.6.308. PMID 16689649. S2CID 119459291.
^Morbey, C. L.; Griffin, R. F. (1987). "On the reality of certain spectroscopic orbits". Astrophysical Journal, Part 1. 317: 343–352. Bibcode:1987ApJ...317..343M. doi:10.1086/165281.
^Carson, J. C.; et al. (2006). "The Cornell High-Order Adaptive Optics Survey for Brown Dwarfs in Stellar Systems. I. Observations, Data Reduction, and Detection Analyses". The Astronomical Journal. 130 (3): 1212–1220. arXiv:astro-ph/0506287. Bibcode:2005AJ....130.1212C. doi:10.1086/432604. S2CID 8888863.
^"Stars searched for extraterrestrials". PhysOrg.com. 2006-02-19. Retrieved 2008-05-04.
External links
edit
"Chara". SolStation. Retrieved 2006-12-06.
"Astronomer announces shortlist of stellar candidates for habitable worlds". SpaceRef.com. 2006-02-18. Retrieved 2006-08-10.[permanent dead link]