The Transiting Circumbinary Planets Kepler-34 and Kepler-35

TL;DR

This paper reports the discovery of two additional transiting circumbinary planets, Kepler-34 and Kepler-35, expanding understanding of planets orbiting binary stars and suggesting such planets are relatively common.

Contribution

The paper presents the detection and characterization of two new circumbinary planets, Kepler-34 and Kepler-35, demonstrating their prevalence around binary stars.

Findings

Kepler-34 orbits two Sun-like stars every 289 days.

Kepler-35 orbits smaller stars every 131 days.

Circumbinary planets are present around at least 1% of close binary stars.

Abstract

Most Sun-like stars in the Galaxy reside in gravitationally-bound pairs of stars called "binary stars". While long anticipated, the existence of a "circumbinary planet" orbiting such a pair of normal stars was not definitively established until the discovery of Kepler-16. Incontrovertible evidence was provided by the miniature eclipses ("transits") of the stars by the planet. However, questions remain about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we present two additional transiting circumbinary planets, Kepler-34 and Kepler-35. Each is a low-density gas giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 orbits two Sun-like stars every 289 days, while Kepler-35 orbits a pair of smaller stars (89% and 81% of the Sun's mass) every 131 days. Due to the orbital motion of the stars, the planets experience large multi-periodic variations in incident stellar radiation. The observed rate of circumbinary planets implies > ~1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.