Beta Canum Venaticorum
Beta Canum Venaticorum
Observation data
Epoch J2000 Equinox J2000 |
| Constellation |
Canes Venatici |
| Right ascension |
12h 33m 44.54482s[1] |
| Declination |
+41° 21′ 26.9248″[1] |
| Apparent magnitude (V) |
4.26[2] |
| Characteristics |
| Spectral type |
G0 V[2] |
| U−B color index |
0.04[3] |
| B−V color index |
0.58[3] |
| Variable type |
Suspected |
| Astrometry |
|
| Radial velocity (Rv) |
+6.9[4] km/s |
| Proper motion (μ) |
RA: -704.75[1] mas/yr
Dec.: 292.74[1] mas/yr |
| Parallax (π) |
118.49 ± 0.20[1] mas |
| Distance |
27.53 ± 0.05 ly
(8.44 ± 0.01 pc) |
| Absolute magnitude (MV) |
4.65 |
|
| Details |
|
| Mass |
1.025 ± 0.050[5] M☉ |
| Radius |
1.18 ± 0.11[6] R☉ |
| Surface gravity (log g) |
4.60[7] |
| Luminosity |
1.15[8] L☉ |
| Temperature |
6,045[7] K |
| Metallicity |
[Fe/H] = –0.21[7] |
| Rotational velocity (v sin i) |
< 3 km/s |
| Age |
5.3×109[9] years |
|
| Other designations |
Chara, Asterion, Beta CVn, 8 CVn, Gliese 475, HR 4785, BD +42°2321, HD 109358, LHS 2579, LTT 13552, GCTP 2895.00, SAO 44230, FK5 470, LFT 924, NSV 5725, HIP 61317. [2] |
| Database references |
| SIMBAD |
data |
| ARICNS |
data |
Beta Canum Venaticorum (β CVn, β Canum Venaticorum) is a G-type main sequence dwarf star in the constellation Canes Venatici. It is the second-brightest star in the constellation.
Along with the brighter star Cor Caroli, the pair form the "southern dog" in this constellation that represents hunting dogs. The 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.[10]
In Chinese, 常陳 (Cháng Chén), meaning Imperial Guards, refers to an asterism consisting of β Canum Venaticorum, α Canum Venaticorum, 10 Canum Venaticorum, 6 Canum Venaticorum, 2 Canum Venaticorum, and 67 Ursae Majoris.[11] Consequently, β Canum Venaticorum itself is known as 常陳四 (Cháng Chén sì, English: the Fourth Star of Imperial Guards.)[12]
Observations
At apparent magnitude 4.26, Beta Canum Venaticorum is the second brightest star in the constellation. It has a stellar classification of G0 V, and so is a G-type main sequence star. 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.[13] (The Ca II emission lines are readily accessible and can be used to measure the level of activity in a star's chromosphere.)
β CVn is considered to be slightly metal-poor,[7] 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.[8] As a result it has been called a solar analog. It is about 3% more massive than the Sun, with a radius 18% larger than the Sun's and 15% greater luminosity.
The components of this star's space velocity are (U, V, W) = (–25, 0, +2) km/s.[8] 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.[14] In addition, a 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.[15]
Possibility of life
In 2006, astronomer Margaret Turnbull labeled Beta CVn as the top stellar system candidate to search for extraterrestrial life forms.[16] Because of its solar-type properties, astrobiologists have listed it among the most astrobiologically interesting stars within 10 parsecs of the Sun.[8] However, as of 2009, this star is not known to host planets.[5]
Chara and Asterion in Military
Chara and Asterion is used for the name of three United States navy ships : USS Asterion (AK-100), USS Asterion (AF-63) and USS Chara (AKA-58).
References
- ^ a b c d e van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, Bibcode 2007A&A...474..653V, doi:10.1051/0004-6361:20078357
- ^ a b c "bet CVn -- Spectroscopic binary". SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+CVn. Retrieved 2010-07-04.
- ^ a b Argue, A. N. (1966). "UBV photometry of 550 F, G and K type stars". Monthly Notices of the Royal Astronomical Society 133: 475–493. Bibcode 1966MNRAS.133..475A.
- ^ Wilson, Ralph Elmer (1953). General Catalogue of Stellar Radial Velocities. Washington: Carnegie Institution of Washington. Bibcode 1953QB901.W495......
- ^ a b 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. Bibcode 2009ApJ...694.1085V. doi:10.1088/0004-637X/694/2/1085.
- ^ Perrin, M.-N.; Karoji, H. (1987). "Stellar radius determination from IRAS 12-micron fluxes". Astronomy and Astrophysics 172: 235–240. Bibcode 1987A&A...172..235P.
- ^ a b c d Luck, R. Earle; Heiter, Ulrike (2006). "Dwarfs in the Local Region". The Astronomical Journal 131 (2): 3069–3092. Bibcode 2006AJ....131.3069L. doi:10.1086/504080.
- ^ a b c d de Mello, G. P.; del Peloso, E. F.; Ghezzi, L. (2006). "Astrobiologically Interesting Stars Within 10 Parsecs of the Sun" (abstract). Astrobiology 6 (2): 308–331. arXiv:astro-ph/0511180. Bibcode 2006AsBio...6..308P. doi:10.1089/ast.2006.6.308. PMID 16689649.
- ^ Barry, Don C.; Cromwell, Richard H.; Hege, E. Keith (1987). "Chromospheric activity and ages of solar-type stars". Astrophysical Journal, Part 1 315: 264–272. Bibcode 1987ApJ...315..264B. doi:10.1086/165131.
- ^ Kaler, Jim. "Beta Canum Venaticorum". Stars. University of Illinois. http://www.astro.uiuc.edu/~kaler/sow/chara.html. Retrieved 2006-12-06.
- ^ (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.
- ^ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ^ 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.
- ^ 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.; Eikenberry, S. S.; Brandl, B. R.; Wilson, J. C.; Hayward, T. L. (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.
- ^ "Stars searched for extraterrestrials". PhysOrg.com. 2006-02-19. http://www.physorg.com/news10993.html. Retrieved 2008-05-04.
External links
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← Star systems within 25–30 light-years →
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GJ 1087 ( 26.1 ± 0.8 ly; 1 star) • Gliese 915 ( 26.7 ± 0.3 ly; 1 star) • Gliese 318 ( 28.7 ± 0.5 ly; 1 star)
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DC
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GJ 2012 (29.5 ± 0.3 ly; 1 star)
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DZ
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Gliese 518 ( 26.9 ± 0.8 ly; 1 star) • GJ 1276 ( 27.9 ± 0.2 ly; 1 star) • Gliese 283 ( 29.7 ± 0.2 ly; 2 stars)
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SDSS J1416+13 ( 25.7 ± 5.5 ly; 2 brown dwarfs)‡ • WISE 1647+5632 ( 28.1 + 9.4/- 5.6 ly; 1 brown dwarf)‡ • 2MASS 0036+1821 ( 28.6 ± 0.2 ly; 1 brown dwarf) |
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In left column are stellar classes of primary members of star systems. ‡Distance error margin extends out of declared distance interval. Bold are systems containing at least one component with absolute magnitude of +8.5 or brighter. Italic are systems possibly located within declared distance interval, but probably not.
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Sirius ( 8.58 ± 0.03 ly; 2 stars)
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Altair ( 16.69 ± 0.04 ly; 1 star)
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In left column are stellar classes of primary members of star systems. ‡Distance error margin extends out of declared distance interval. Italic are systems possibly located within declared distance interval, but likely not. Total about 50 (47–52) systems.
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