Six New ZZ Ceti Stars from the SPY and the HQS Surveys

Abstract

We report on the discovery of six new ZZCeti stars. They were selected as candidates based on preparatory photometric observations of ob- jects from the Hamburg Quasar Survey (HQS), and based on the spectra of the Supernova Ia Progenitor Survey (SPY). Time-series photometry of 19 can- didate stars was carried out at the Nordic Optical Telescope (NOT) at Roque de Los Muchachos Observatory, Spain. The new variables are relatively bright, 15.4 < B < 16.6. Among them is WD 1150−153, which is the third ZZCeti star that shows photospheric CaII in its spectrum.