Beta Canum Venaticorum
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Canes Venatici |
| Right ascension | 12h 33m 44.5446s |
| Declination | +41° 21′ 26.927″ |
| Apparent magnitude (V) | 4.26 |
| Characteristics | |
| Spectral type | G0 V |
| U−B color index | 0.04[1] |
| B−V color index | 0.58[1] |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | +6.9 km/s |
| Proper motion (μ) | RA: -705.06 mas/yr Dec.: 292.93 mas/yr |
| Parallax (π) | 119.19 ± 0.83 mas |
| Distance | 27.4 ± 0.2 ly (8.39 ± 0.06 pc) |
| Absolute magnitude (MV) | 4.65 |
| Details | |
| Mass | 1.08 M☉ |
| Radius | 1.11 R☉ |
| Luminosity | 1.15[2] L☉ |
| Surface gravity (log g) | 4.60[3] cgs |
| Temperature | 6,045[3] K |
| Metallicity | [Fe/H] = −0.21[3] |
| Rotation | < 3 km/s |
| Age | 5.3×109[4] years |
| Other designations | |
Chara, Asterion, Beta CVn, 8 CVn, Gl 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. | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
Beta Canum Venaticorum (β CVn / β Canum Venaticorum) is a yellow 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 means Joy in the Greek language.[5]
Observations
β CVn is considered to be slightly metal-poor,[3] 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.[6] As a result it has been called a solar analog.
The components of this star's space velocity are U=−25, V=0 and W=+2 km/s.[2] In the past it was suggested that this star may be a spectroscopic binary. However, further analysis of the data does not seem to bear that out.[7] 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.[8]
The spectrum of this star shows a very weak emission 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.[9] (The Ca II emission lines are readily accessible and can be used to measure the level of activity in a star's chromosphere.)
Possibility of life
In 2006, astronomer Margaret Turnbull labelled Beta CVn as the top stellar system top candidate to search for extraterrestrial life forms.[10] Because of its solar-type properties, astrobiologists have listed it among the most astrobiologically interesting stars within 10 parsecs of the Sun.[2]
References
- ^ 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. Retrieved 2008-05-05.
- ^ a b c de Mello, G. P. (2006). "Astrobiologically Interesting Stars Within 10 Parsecs of the Sun". Astrobiology. 6 (2): 308–331. Retrieved 2008-05-05.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ a b c d Luck, R. Earle (2006). "Dwarfs in the Local Region". The Astronomical Journal. 131 (2): 3069–3092. doi:10.1086/504080.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Barry, Don C. (1987). "Chromospheric activity and ages of solar-type stars". Astrophysical Journal, Part 1. 315: 264–272. Retrieved 2008-05-05.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Kaler, Jim. "Beta Canum Venaticorum". Stars. Retrieved 2006-12-06.
- ^ G. F. Porto de Mello, E. F. del Peloso, L. Ghezzi (2006). "Astrobiologically interesting stars within 10 parsecs of the Sun". Astrobiology. 6 (2): 308–331.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Morbey, C. L. (1987). "On the reality of certain spectroscopic orbits". Astrophysical Journal, Part 1. 317: 343–352. Retrieved 2008-05-05.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Carson, J. C. (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: 31212–1220. doi:10.1086/432604.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ 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.
- ^ "Stars searched for extraterrestrials". PhysOrg.com. February 19, 2006. Retrieved 2008-05-04.
External links
- "Chara". SolStation. Retrieved 2006-12-06.
- "Astronomer announces shortlist of stellar candidates for habitable worlds". SpaceRef.com. February 18, 2006. Retrieved 2006-08-10.
- "β Canum Venaticorum". Alcyone. Retrieved 2006-08-10.
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