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arXiv · 1404.7470

K2 observations of the pulsating subdwarf B star EQ Piscium: an sdB+dM binary

C. S. Jeffery·Gavin Ramsay
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Abstract

K2, the two-wheel mission of the Kepler space telescope, observed the pulsating subdwarf B star EQ Psc during engineering tests in 2014 February. In addition to a rich spectrum of g-mode pulsation frequencies, the observations demonstrate a light variation with a period of 19.2 h and a full amplitude of 2%. We suggest that this is due to reflection from a cool companion, making EQ\,Psc the longest-period member of some 30 binaries comprising a hot subdwarf and a cool dwarf companion (sdB+dM), and hence useful for exploring the common-envelope ejection mechanism in low-mass binaries.

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C. S. Jeffery, Gavin Ramsay. 2014-04-29. K2 observations of the pulsating subdwarf B star EQ Piscium: an sdB+dM binary. https://doi.org/10.1093/mnrasl/slu059

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