La Superba
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Stern Y Canum Venaticorum / La Superba |
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | Hunting dogs | ||||||||||||||||
| Right ascension | 12 h 45 m 7.83 s | ||||||||||||||||
| declination | + 45 ° 26 ′ 24.9 ″ | ||||||||||||||||
| Apparent brightness | 4.87 (4.86-5.88) mag | ||||||||||||||||
| Typing | |||||||||||||||||
| B − V color index | +2.54 | ||||||||||||||||
| U − B color index | +6.62 | ||||||||||||||||
| R − I index | +1.38 | ||||||||||||||||
| Spectral class | C5.4J (N3) | ||||||||||||||||
| Variable star type | SRB | ||||||||||||||||
| Astrometry | |||||||||||||||||
| Radial velocity | (+15.3 ± 0.4) km / s | ||||||||||||||||
| parallax | (4.31 ± 0.24) mas | ||||||||||||||||
| distance | (760 ± 50) ly approx. 300 pc |
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| Proper movement | |||||||||||||||||
| Rec. Share: | (−2.68 ± 0.24) mas / a | ||||||||||||||||
| Dec. portion: | (14.78 ± 0.28) mas / a | ||||||||||||||||
| Physical Properties | |||||||||||||||||
| radius | (300) R ☉ | ||||||||||||||||
| Luminosity |
(4850) L ☉ |
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| Effective temperature | (2750) K. | ||||||||||||||||
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Other names and catalog entries |
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La Superba is the name of the variable star Y Canum Venaticorum (Y CVn) in the constellation Hounds .
It is one of the reddest stars in the sky. The Italian astronomer Angelo Secchi called it La Superba , "the outstanding one", because of its striking coloring . Catalog names are HR 4846 or HD 110914.
The star is a red giant about 760 light years away . It belongs to the spectral class C and has a high carbon content . Such stars are also known as carbon stars . The surface temperature is only 2800 K . The diameter is about 300 times that of the sun. This would make the star in our solar system rise above the earth's orbit .
The apparent brightness fluctuates between 4.86 mag and 5.88 mag over a period of about 157 days. La Superba is counted among the semi-regularly changing stars .
See also
Web links
Individual evidence
- ↑ a b c d e f g Y CVn. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed September 8, 2018 .
- ↑ a b c Y CVn. In: VSX. AAVSO, accessed September 8, 2018 .
- ↑ Pulkovo radial velocities for 35493 HIP stars
- ^ A b c E. De Beck, L. Decin, A. De Koter, K. Justtanont, T. Verhoelst, F. Kemper, KM Menten: Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles . II. CO line survey of evolved stars: Derivation of mass-loss rate formulas . In: Astronomy and Astrophysics . 523, 2010, p. A18. arxiv : 1008.1083 . bibcode : 2010A & A ... 523A..18D . doi : 10.1051 / 0004-6361 / 200913771 .