The EC14026 stars - VI. PG1047+003

Abstract

We report the discovery of rapid oscillations in the sdB star PG1047+003. The oscillations are multiperiodic, with nine periods in the range 104-162s. The optical spectrum of PG1047+003 is consistent with that of a single sdB star. Line profile fitting yields an effective temperature of 35000+/-1000K and log g=5.9+/-0.1, although optical photometry and IUE spectrophotometry may indicate a cooler effective temperature. These properties demonstrate that PG1047+003 is an EC14026 star, a recently discovered class of sdB pulsators. Optical and infrared photometry constrains any cool companion to the sdB star to be a main-sequence star of spectral type M0 or later. With V=13.47 and a relatively rich pulsation spectrum, PG1047+003 is an attractive target for an intensive photometric campaign to extract more periods from the light curve which, along with a suitable grid of pulsation models, will probe the interior structure of the star.