Heartbeat Stars

NASA's Kepler Satellite has discovered a new class of binary star systems: eccentric binaries with dynamic tidal distortions, deformations due to interactions with the secondary star, and tidally-induced pulsations. Because of the unique light curves of these systems, they have gained the nickname of "heartbeat stars". We are collaborating with the Kepler science team to better characterize these systems using velocity variations in the primary star's spectrum. We use the Wyoming Infrared Observatory to obtain multiple spectra of the heartbeat stars. From our data, we can extract parameters such as the period and eccentricity of the binary star system, the mass ratios of the stars, and perhaps understand better the effect of the tides that distort the spherical shape of the star and stimulate pulsations in the primary star. We present the results of our pilot survey of four of these heartbeat stars. Our findings can eventually lead us to a formation scenario for this type of binary system, which, in turn, will allow us to more fully understand stellar evolution as a whole.