W Virginis
Star W Virginis |
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AladinLite | |||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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Constellation | Virgin | ||||||||||||||
Right ascension | 13 h 26 m 1.99 s | ||||||||||||||
declination | -03 ° 22 ′ 43.4 ″ | ||||||||||||||
Apparent brightness | 9.46 (9.46-10.75) mag | ||||||||||||||
Typing | |||||||||||||||
B − V color index | +0.43 to +0.99 | ||||||||||||||
R − I index | −0.1 | ||||||||||||||
Spectral class | F0 Ib to G0 Ib | ||||||||||||||
Variable star type | CWA | ||||||||||||||
Astrometry | |||||||||||||||
Radial velocity | −65.5 km / s | ||||||||||||||
parallax | (0.40 ± 0.07) mas | ||||||||||||||
distance | 8,000 ly 2,500 pc |
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Visual absolute brightness M vis | −3.0 mag | ||||||||||||||
Proper movement | |||||||||||||||
Rec. Share: | −3.94 ± 0.09 mas / a | ||||||||||||||
Dec. portion: | +1.03 ± 0.10 mas / a | ||||||||||||||
Physical Properties | |||||||||||||||
Dimensions | 0.4 M ☉ | ||||||||||||||
radius | 22 to 52 R ☉ | ||||||||||||||
Luminosity |
470 to 1250 L ☉ |
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Effective temperature | 4280 to 6550 K | ||||||||||||||
Metallicity [Fe / H] | −1.0 | ||||||||||||||
Other names and catalog entries |
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W Virginis is a star about 8,000 light years away . It is the prototype of the W-Virginis stars , which belong to the pulsation-variable stars .
W Virginis shows a fluctuation of the magnitude from about 9.5 at the maximum to 10.75 at the minimum over a period of 17 days . These strong fluctuations also ensure that the star would be assigned to a different spectral class depending on the situation - it fluctuates between F0 and G0.
See also
Web links
Individual evidence
- ↑ a b c d e W Vir. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed September 11, 2018 .
- ↑ a b c N. N. Samus, OV Durlevich: VizieR Online Data Catalog: General Catalog of Variable Stars (Samus + 2007-2013) . In: VizieR . 1, 2009, p. 02025. bibcode : 2009yCat .... 102025S .
- ↑ a b W Vir. In: VSX. AAVSO, accessed September 11, 2018 .
- ↑ a b c d Timothy Barker et. al: Abundance Analysis of Population II Variable Stars. I. W Virginis . In: Astrophysical Journal . 165, 1971, p. 67. bibcode : 1971ApJ ... 165 ... 67B . doi : 10.1086 / 150877 .
- ^ F. Van Leeuwen: Validation of the new Hipparcos reduction . In: Astronomy and Astrophysics . 474, No. 2, 2007, p. 653. arxiv : 0708.1752 . bibcode : 2007A & A ... 474..653V . doi : 10.1051 / 0004-6361: 20078357 .
- ^ Z. Balog, J. Vinko, G. Kaszas: Baade-Wesselink Radius Determination of Type II Cepheids . In: Astronomical Journal . 113, 1997, p. 1833. bibcode : 1997AJ .... 113.1833B . doi : 10.1086 / 118394 .
- ↑ E. Böhm-Vitense, P. Szkody, G. Wallerstein, I. Iben: Masses and luminosities of population II cepheids . In: Astrophysical Journal . 194, 1974, p. 125. bibcode : 1974ApJ ... 194..125B . doi : 10.1086 / 153229 .
- ↑ Thomas Maas, Sunetra Giridhar, David L. Lambert: The Chemical Compositions of the Type II Cepheids-The BL Herculis and W Virginis Variables . In: The Astrophysical Journal . 666, 2007, p. 378. arxiv : 0706.2029 . bibcode : 2007ApJ ... 666..378M . doi : 10.1086 / 520081 .