HE 0230−4323 revisited: a new rapidly pulsating sdB star

Abstract

HE 0230−4323 is a hot sdB star in a binary system. An earlier work demonstrated that the light curve of the system shows a strong (∼4 per cent) reflection effect and also appears to exhibit photometric variations of the type associated with the slowly pulsating class of sdB star (multiple periods in the range ∼1–2 h). In this paper, we show that HE 0230−4323 is, in fact, a rapidly pulsating sdB with at least five frequencies between 3227 and 3532 μHz (periods between 310 and 283 s). The long periods previously claimed were the result of undersampling the light curve at a time interval very close to that of the short periods. The interpretation of the very slow variation (∼0.45 d) as a reflection effect in a close binary is unaffected by these new results.