Beta Canum Venaticorum

Starbox begin
name=Beta Canum Venaticorum Starbox observe
epoch=J2000
ra=RA|12|33|44.5446
dec=DEC| +41|21|26.927
appmag_v=4.26
constell=Canes Venatici Starbox character
class=G0 V
b-v=0.58cite journal
last=Argue | first=A. N.
title=UBV photometry of 550 F, G and K type stars
journal=Monthly Notices of the Royal Astronomical Society
year=1966 | volume=133 | pages=475–493
url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1966MNRAS.133..475A
accessdate=2008-05-05 ]
u-b=0.04
variable=Suspected Starbox astrometry
radial_v=+6.9
prop_mo_ra=-705.06
prop_mo_dec=292.93
parallax=119.19
p_error=0.83
absmag_v=4.65 Starbox detail
mass=1.08
radius=1.18 ± 0.11 [cite journal
last=Perrin | first=M.-N. | coauthors=Karoji, H.
title=Stellar radius determination from IRAS 12-micron fluxes
journal=Astronomy and Astrophysics
year=1987 | volume=172 | pages=235–240
url=http://adsabs.harvard.edu/abs/1987A&A...172..235P
accessdate=2008-05-05 ]
luminosity=1.15
temperature=6,045cite journal
last=Luck | first=R. Earle | coauthors=Heiter, Ulrike
title=Dwarfs in the Local Region
journal=The Astronomical Journal
year=2006 | volume=131 | issue=2 | pages=3069–3092
doi=10.1086/504080 ]
gravity=4.60
metal= [Fe/H] = −0.21
rotation=< 3 km/s
age=5.3e|9cite journal
last=Barry | first=Don C.
coauthors=Cromwell, Richard H.; Hege, E. Keith
title=Chromospheric activity and ages of solar-type stars
journal=Astrophysical Journal, Part 1
year=1987 | volume=315 | pages=264–272
url=http://adsabs.harvard.edu/abs/1987ApJ...315..264B
accessdate=2008-05-05
doi=10.1086/165131 ] Starbox catalog
names=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. Starbox reference
Simbad=HD+109358
ARICNS=00978

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 withthe 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. [cite web
last = Kaler | first = Jim
url = http://www.astro.uiuc.edu/~kaler/sow/chara.html
title = Beta Canum Venaticorum | publisher = Stars
accessdate = 2006-12-06 ]

Observations

β CVn is considered to be slightly metal-poor, 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. [cite journal | author=G. F. Porto de Mello, E. F. del Peloso, L. Ghezzi | title=Astrobiologically interesting stars within 10 parsecs of the Sun | journal=Astrobiology | year=2006 | volume=6 | issue=2 | pages=308–331 | url=http://www.liebertonline.com/doi/abs/10.1089/ast.2006.6.308 | doi=10.1089/ast.2006.6.308 | format=abstract ] 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.cite journal
last=de Mello | first=G. P.
coauthors=del Peloso, E. F.; Ghezzi, L.
title=Astrobiologically Interesting Stars Within 10 Parsecs of the Sun
journal=Astrobiology
year=2006 | volume=6 | issue=2 | pages=308–331
url=http://arxiv.org/abs/astro-ph/0511180
accessdate=2008-05-05
doi=10.1089/ast.2006.6.308
format=abstract ] In the past it was suggested that this star may be a
spectroscopic binary. However, further analysis ofthe data does not seem to bear that out. [cite journal
last=Morbey | first=C. L. | coauthors=Griffin, R. F.
title=On the reality of certain spectroscopic orbits
journal=Astrophysical Journal, Part 1
year=1987 | volume=317 | pages=343&ndash;352
url=http://adsabs.harvard.edu/abs/1987ApJ...317..343M
accessdate=2008-05-05
doi=10.1086/165281 ] 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.cite journal
last=Carson | first=J. C.
coauthors=Eikenberry, S. S.; Brandl, B. R.; Wilson, J. C.; Hayward, T. L.
title=The Cornell High-Order Adaptive Optics Survey for Brown Dwarfs in Stellar Systems. I. Observations, Data Reduction, and Detection Analyses
journal=The Astronomical Journal | year=2006 | volume=130
pages=31212&ndash;1220 | doi=10.1086/432604 ]

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. [cite journal | last=Herbig | first=G. H. | title=Chromospheric H-alpha emission in F8-G3 dwarfs, and its connection with the T Tauri stars | journal=Astrophysical Journal | year=1985 | volume=289 | issue=1 | pages=269–278 | url=http://adsabs.harvard.edu/abs/1985ApJ...289..269H | doi=10.1086/162887 ] (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. [cite news
title=Stars searched for extraterrestrials
publisher= PhysOrg.com | date=2006-02-19
url=http://www.physorg.com/news10993.html
accessdate=2008-05-04 ] Because of its solar-type properties, astrobiologists have listed it among the most astrobiologically interesting stars within 10 parsecs of the Sun.

References

External links

*cite web | url = http://www.solstation.com/stars/chara.htm | title = Chara | publisher = SolStation | accessdate = 2006-12-06
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