A PLANET IN AN 840 DAY ORBIT AROUND A KEPLER MAIN-SEQUENCE A STAR FOUND FROM PHASE MODULATION OF ITS PULSATIONS

Abstract

We have detected a 12 M Jup planet orbiting in or near the habitable zone of a main-sequence A star via the pulsational phase shifts induced by orbital motion. The planet has an orbital period of 840 ± 20 days and an eccentricity of 0.15. All known planets orbiting main-sequence A stars have been found via the transit method or by direct imaging. The absence of astrometric or radial velocity detections of planets around these hosts makes ours the first discovery using the orbital motion. It is also the first A star known to host a planet within 1 σ of the habitable zone. We find evidence for planets in a large fraction of the parameter space where we are able to detect them. This supports the idea that A stars harbor high-mass planets in wide orbits.