Eclipsing binaries in the All Sky Automated Survey catalogue |
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| Authors: | B Paczy&#;ski D M Szczygie&#; B Pilecki G Pojma&#;ski |
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| Institution: | Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA;Warsaw University Observatory, Al. Ujazdowskie 4, PL-00-478, Poland |
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| Abstract: | The All Sky Automated Survey (ASAS) is a long-term project to monitor bright variable stars over the whole sky. It has discovered 50 099 variables brighter than V < 14 mag south of declination +28°, and among them 11 076 eclipsing binaries. We present a preliminary analysis of 5384 contact, 2949 semi-detached, and 2743 detached systems. The statistics of the distribution provides a qualitative confirmation of decades old idea of Flannery and Lucy that the W UMa-type binaries evolve through a series of relaxation oscillations: the ASAS finds comparable number of contact and semi-detached systems.
The most surprising result is a very small number of detached eclipsing binaries with periods P < 1 d , the systems believed to be the progenitors of the W UMa stars. As many (perhaps all) contact binaries have companions, there is a possibility that some were formed in a Kozai cycle, as suggested by Eggleton and his associates. |
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| Keywords: | binaries: eclipsing stars: evolution |
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