W Virginis

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Star
W Virginis
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
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
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 ☉

Effective temperature 4280 to 6550  K
Metallicity [Fe / H] −1.0
Other names
and catalog entries
Bonn survey BD −2 ° 3683
Henry Draper Catalog HD 116802 [1]
Hipparcos catalog HIP 65531 [2]
SAO catalog SAO 139335 [3]
Tycho catalog TYC 4962-550-1 [4]Template: Infobox star / maintenance / specification of the TYC catalog
2MASS catalog 2MASS J13260199-0322434 [5]
Other names W Virginis

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

  1. ↑ a b c d e W Vir. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed September 11, 2018 .
  2. ↑ 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 .
  3. ↑ a b W Vir. In: VSX. AAVSO, accessed September 11, 2018 .
  4. ↑ 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 .
  5. ^ 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 .
  6. ^ 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 .
  7. ↑ 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 .
  8. ↑ 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 .