A planet in an 840-d orbit around a Kepler main-sequence A star found from phase modulation of its pulsations

TL;DR

This paper reports the first detection of a planet orbiting a main-sequence A star using pulsational phase shifts, revealing a 12 Jupiter-mass planet in an 840-day orbit near the habitable zone, supporting the prevalence of high-mass planets around A stars.

Contribution

It introduces a novel method of detecting planets via pulsational phase shifts, expanding detection techniques for A star planetary systems.

Findings

First planet detection around an A star using phase modulation.

Planet has a 12 M$_{ m Jup}$ mass and 840-day orbit.

Supports high occurrence rate of massive, wide-orbit planets around A stars.

Abstract

We have detected a 12 M$_{\rm Jup}$ 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 $840\pm20$ d 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$\sigma$ 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.