Beaming Binaries: A New Observational Category of Photometric Binary Stars

Abstract

The new photometric spaceborne survey missions COROT and Kepler will be able to detect minute flux variations in binary stars due to relativistic beaming caused by the line-of-sight motion of their components. In all but very short period binaries (P>10 days), these variations will dominate over the ellipsoidal and reflection periodic variability. Thus, COROT and Kepler will discover a new observational class: photometric beaming binary stars. We examine this new category and the information that the photometric variations can provide. The variations that result from the observatory heliocentric velocity can be used to extract some spectral information even for single stars.