Beta Canum Venaticorum
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Canes Venatici |
| Right ascension | 12h 33m 44.54425s[1] |
| Declination | +41° 21′ 26.9214″[1] |
| Apparent magnitude (V) | 4.25[2] |
| Characteristics | |
| Spectral type | G0 V[3] |
| U−B color index | 0.04[4] |
| B−V color index | 0.58[4] |
| Astrometry | |
| Radial velocity (Rv) | +6.15±0.12[1] km/s |
| Proper motion (μ) | RA: −704.702[1] mas/yr Dec.: +292.155[1] mas/yr |
| Parallax (π) | 118.0266±0.1530 mas[1] |
| Distance | 27.63 ± 0.04 ly (8.47 ± 0.01 pc) |
| Absolute magnitude (MV) | 4.64[5] |
| Details | |
| Mass | 0.97±0.04[6] M☉ |
| Radius | 1.03±0.03[7] R☉ |
| Luminosity | 1.254±0.009[8] L☉ |
| Surface gravity (log g) | 4.41±0.04[8] cgs |
| Temperature | 6013±91[8] K |
| Metallicity [Fe/H] | −0.2±0.01[8] dex |
| Rotational velocity (v sin i) | 2.9±0.4[9] km/s |
| Age | 3.4[6] to 7.1[5] Gyr |
| Other designations | |
| Chara, β CVn, 8 CVn, BD+42 2321, FK5 470, GJ 475, HD 109358, HIP 61317, HR 4785, SAO 44230, NGC 4530[10] | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
Beta Canum Venaticorum (β Canum Venaticorum, abbreviated Beta CVn, β CVn), also named Chara /ˈkɛərə/,[11][12] is the second-brightest star in the northern constellation of Canes Venatici. It is a nearby solar-type star, about 27.6 light-years (8.5 parsecs) distant based on its parallax. The star is faintly visible to the naked eye, at an apparent magnitude of +4.25. Along with the brighter star Cor Caroli, the pair form the "southern dog" in this constellation that represents hunting dogs.
Nomenclature
[edit]β Canum Venaticorum (Latinised to Beta Canum Venaticorum) is the star's Bayer designation. It also has the Flamsteed designation 8 Canum Venaticorum.[10] The star was listed in the New General Catalogue as NGC 4530.[13][14]
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.[15] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[16] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[17] included a table of the first two batches of names approved by the WGSN; which included Chara for this star.
In Chinese, 常陳 (Cháng Chén), meaning Imperial Guards, refers to an asterism consisting of Beta Canum Venaticorum, Alpha Canum Venaticorum, 10 Canum Venaticorum, 6 Canum Venaticorum, 2 Canum Venaticorum, and 67 Ursae Majoris.[18] Consequently, the Chinese name for Beta Canum Venaticorum itself is 常陳四 (Cháng Chén sì, English: the Fourth Star of Imperial Guards.)[19]
Characteristics
[edit]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.[20] 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.[21] (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,[8] 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.[22] 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.[7][8]
The components of this star's space velocity are (U, V, W) = (–25, 0, +2) km/s.[22] 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.[23] 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.[24]
Habitability
[edit]In 2006, astronomer Margaret Turnbull labeled Beta CVn as the top stellar system candidate to search for extraterrestrial life forms.[25] Because of its solar-type properties, astrobiologists have listed it among the most astrobiologically interesting stars within 10 parsecs of the Sun.[22] However, as of 2009, this star is not known to host planets.[2]
See also
[edit]References
[edit]- ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c van 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.
- ^ a b Argue, A. N. (1966). "UBV photometry of 550 F, G and K type stars". Monthly Notices of the Royal Astronomical Society. 133 (4): 475–493. Bibcode:1966MNRAS.133..475A. doi:10.1093/mnras/133.4.475.
- ^ a b Holmberg, 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.
- ^ a b Llorente 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.
- ^ a b Baines, 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.
- ^ a b c d e f Soubiran, 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.
- ^ a b "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.
- ^ Seligman, Courtney. "New General Catalog Objects: NGC 4500 - 4549". Retrieved 15 March 2025.
- ^ "NGC 4530". NGC/IC Project - VizieR.
- ^ 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.
- ^ a b c de 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. Archived from the original on May 24, 2012. Retrieved 2006-08-10.
