From Wikipedia, the free encyclopedia
W Virginis variables are a subclass of Type II Cepheids which exhibit pulsation periods between 10–20 days,[ 1] spectral class F6 – K2.[ 2] [ 3]
They were first recognized as being distinct from classical Cepheids by Walter Baade in 1942, in a study of Cepheids in the Andromeda Galaxy that proposed that stars in that galaxy were of two populations.[ 4]
See also
References
^ Wallerstein, G., "The Cepheids of Population II and Related Stars" , Publications of the Astronomical Society of the Pacific , 114 p.689–699 (2002)
^ W. Strohmeier, Variable Stars , Pergamon (1972)
^ Soszyński, I.; Udalski, A.; Szymański, M. K.; Kubiak, M.; Pietrzyński, G.; Wyrzykowski, Ł.; Szewczyk, O.; Ulaczyk, K.; Poleski, R. "The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. II.Type II Cepheids and Anomalous Cepheids in the Large Magellanic Cloud" , Acta A. , vol 58 (2008)
^ Webb, Stephen, Measuring the Universe: The Cosmological Distance Ladder , Springer, (1999)
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