Search for Binaries in the Kepler K2 Fields Using Pulsation Timing Method

Finding orbital solutions of binaries which have small mass ratios (50 days) is challenging using traditional techniques. The radial velocity method is a good way to detect such binary stars, however it requires large telescopes. Therefore, the search for binaries in those regions is still incomplete. For binaries in this regime with at least one component that pulsates, pulsation timing is a better approach. Orbital solutions for such systems can be obtained from the periodic change in pulse arrival times as the star’s reflex motion is manifested by the changing distance along the line of sight. We present a search for binaries with δ Scuti variables in the Kepler K2 extended mission fields. We used the K2 long-cadence (sampling time = 29.45-min) light curves, which are suitable to detect pulsation periods of a few hours as in δ Scuti stars. The observation span for the Kepler K2 mission is about 80 days. Binary candidates which show evidence of periods longer than the K2 temporal window can be observed using space telescopes like TESS and ground-based 1-m class telescopes.