Asterion
Star asterion (β CVn) |
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AladinLite | |||||||||||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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Constellation | Hunting dogs | ||||||||||||||||||||||
Right ascension | 12 h 33 m 44.55 s | ||||||||||||||||||||||
declination | + 41 ° 21 ′ 26.9 ″ | ||||||||||||||||||||||
Apparent brightness | 4.24 likes | ||||||||||||||||||||||
Typing | |||||||||||||||||||||||
B − V color index | +0.59 | ||||||||||||||||||||||
U − B color index | +0.05 | ||||||||||||||||||||||
R − I index | +0.31 | ||||||||||||||||||||||
Spectral class | G0 V | ||||||||||||||||||||||
Astrometry | |||||||||||||||||||||||
Radial velocity | (6.3 ± 0.1) km / s | ||||||||||||||||||||||
parallax | (118.49 ± 0.20) mas | ||||||||||||||||||||||
distance | (27.53 ± 0.05) ly (8.44 ± 0.01) pc |
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Visual absolute brightness M vis | +4.61 mag | ||||||||||||||||||||||
Proper movement | |||||||||||||||||||||||
Rec. Share: | (−704.75 ± 0.13) mas / a | ||||||||||||||||||||||
Dec. portion: | (292.74 ± 0.14) mas / a | ||||||||||||||||||||||
Physical Properties | |||||||||||||||||||||||
Dimensions | (~ 1) M ☉ | ||||||||||||||||||||||
radius | (1.03) R ☉ | ||||||||||||||||||||||
Luminosity |
(1.18) L ☉ |
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Effective temperature | (5880) K. | ||||||||||||||||||||||
Age | (~ 7) bill. A | ||||||||||||||||||||||
Other names and catalog entries |
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Asterion is a yellow dwarf of the main sequence and the name for the star β Canum Venaticorum (Beta Canum Venaticorum). With an apparent magnitude of +4.26 mag, it is the second brightest star in the constellation Hounds. At a distance of around 27 light years , it is a star relatively close to the Sun. Together with the lighter star Cor Caroli , it forms the constellation Hunting Dogs.
Proper name
Another name for Asterion is Chara , the Greek word for joy. This name originally referred to the "southern dog" of the constellation, but later only referred to the star β Canum Venaticorum.
The IAU has the proper name on July 20, 2016 Chara defined as standardized proper name for this star.
Properties and comparison to the sun
Asterion is very similar to the sun . It is a single star belonging to the spectral class G. Its surface temperature is 5880 Kelvin, which is only 80 Kelvin more than the sun. Asterion is also very similar to the Sun in terms of mass, stage of development, age and orbital speed around the center of the galaxy. It has a slightly larger radius and is a bit older. Asterion, like the sun, has a hot corona atmosphere .
Asterion is considered to be low in metal, i.e. with a low proportion of elements heavier than helium . It has only about 60 percent as much iron as the sun. Asterion's luminosity is around 20 percent higher than that of the sun. The metal content and the luminosity are the biggest differences compared to the sun.
Earlier assumptions that Asterion was a spectroscopic binary star could not be confirmed by more recent observations. A search for a brown dwarf that could possibly orbit the main star also remained fruitless.
Possible life
In 2006, astronomer Margaret Turnbull listed the star Asterion as a top candidate for finding extraterrestrial life. Because of its great resemblance to the Sun, astrobiologists placed it among the astrobiologically interesting stars within 10 parsecs of the Sun.
Trivia
John Herschel believed in July 1828 to spot the star a faint nebula . As a result, the supposed nebula was recorded in the New General Catalog as NGC 4530 .
Web links
- Chara 2? On: SolStation.com (English)
- b Canum Venaticorum - data on: www.alcyone.de (English)
Individual evidence
- ↑ a b c Hipparcos catalog (ESA 1997)
- ↑ a b c Bright Star Catalog
- ↑ Pulkovo radial velocities for 35493 HIP stars
- ↑ a b c Hipparcos, the New Reduction (van Leeuwen, 2007)
- ↑ a b c d e f g h i Chara. Jim Kaler, accessed September 22, 2019 .
- ↑ Bulletin of the IAU Working Group on Star Names, No. 1, July 2016. (PDF) Retrieved November 9, 2016 (English, 184 KiB).
- ↑ a b Gustavo Porto de Mello, Eduardo Fernandez del Peloso, Luan Ghezzi: Astrobiologically Interesting Stars Within 10 parsecs of the Sun . In: Astrobiology . Issue 6, 2006. pp. 308-331. doi : 10.1089 / ast.2006.6.308
- ↑ R. Earle Luck; Ulrike Heiter: Dwarfs in the Local Region . In: The Astronomical Journal . Issue 131, 2006. pp. 3069-3092. doi : 10.1086 / 504080
- ↑ CL Morbey, RF Griffin: On the reality of certain spectroscopic orbits . In: Astrophysical Journal . Part 1, Issue 317, June 1, 1987. pp. 343-352. doi : 10.1086 / 165281 , bibcode : 1987ApJ ... 317..343M .
- ^ JC Carson, SS Eikenberry, BR Brandl, JC Wilson; TL Hayward: The Cornell High-Order Adaptive Optics Survey for Brown Dwarfs in Stellar Systems. I. Observations, Data Reduction, and Detection Analyzes . In: The Astronomical Journal . Edition 130. 2006. pp. 1212-1220 doi : 10.1086 / 432604
- ↑ Stars searched for extraterrestrials . On: PhysOrg.com. February 19, 2006
- ↑ https://cseligman.com/text/atlas/ngc45.htm#4530