C. S. Jeffery and G. Ramsay

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

Figure 3. The adopted fit to the K2 light curve for EQ Psc shown in Fig. 1. Black dots are the K2 observations. The solid red curve shows the solution represented in Table 1.

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 EQPsc 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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Last Revised: 2014 May 1st