Four New δ Scuti Pulsators from a Variability Survey of 131 Stars

Abstract

ABSTRACTIn a photometric variability survey of 131 stars with B≲14 mag, we have found four new δ Scuti stars. We were sensitive to oscillation amplitudes as low as a few millimagnitudes (mmag). The detection rate of short‐period (P<0.1 days) pulsating variable stars, which may be relevant for planned large‐variability surveys such as the Global Astrometric Interferometer for Astrophysics, the Panoramic Optical Imager, and even the Large‐Aperture Synoptic Survey Telescope, was therefore 3%. All four new variable stars have low pulsation amplitude (tens of mmag), and one has a very short period (0.0198 days). This star is one of the fastest known δ Scuti pulsators. The short period of this variable star makes it observationally tractable, and it may therefore be a particularly good candidate for asteroseismological studies. All four new variable stars will add to the cadre of low‐amplitude and relatively short period δ Scuti stars that are potentially useful for learning about the structure of stars on or near the main sequence, slightly more massive than the Sun.