Two new variable sdB stars, HE 0218−3437 and LB 1516

Abstract

We present photometry which shows that two known hot subdwarf stars, HE 0218−3437 and LB 1516, are variable. LB 1516 exhibits several frequencies in the range 12–25 cycles d−1 (periods of about 1–2 h) with amplitudes less than about 0.003 mag and appears to be a typical slowly pulsating sdB star. Results from a multisite campaign on HE 0218−3437 show the presence of two frequencies only, the lower amplitude variation an apparent subharmonic of the higher amplitude periodicity. It is likely that the star is in a binary system, and that the variability is due to ellipsoidal deformation of the primary star.