SuperWASP Lightcurves of Subdwarf Stars

Abstract

SuperWASP is a wide angle survey for transiting hot-Jupiter exoplanets around bright (V<13) solar-type stars. Lightcurves for millions of stars with a few thousand observations per star are available in the SuperWASP archive. We report the results of a search for periodic variable subdwarf stars in the data from the 2004 observing season. A Fourier transform of the SuperWASP lightcurve for Balloon 090100001 recovers the main pulsation frequency of this star. No new pulsators are found among the stars studied (about 200 objects). The binary sdB star HS 2333+3927 with a large reflection effect was recovered. We find that the hot subdwarf PG1348+369 is variable with a period of 3.316 days and a semi-amplitude of 13%. Follow-up spectroscopy shows that this variation is due to irradiation of a cool companion star in a binary system