Kepler-16: A Transiting Circumbinary Planet

TL;DR

This paper reports the discovery of a Saturn-sized planet orbiting a binary star system, with detailed measurements of the system's dynamics, providing insights into planet formation around binary stars.

Contribution

First detection of a transiting circumbinary planet with precise constraints on system dimensions and orbital characteristics.

Findings

The planet is comparable to Saturn in mass and size.

The planet orbits its binary stars every 229 days.

All three bodies' motions are aligned within 0.5 degrees.

Abstract

We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses of the stars, giving precise constraints on the absolute dimensions of all three bodies. The planet is comparable to Saturn in mass and size, and is on a nearly circular 229-day orbit around its two parent stars. The eclipsing stars are 20% and 69% as massive as the sun, and have an eccentric 41-day orbit. The motions of all three bodies are confined to within 0.5 degree of a single plane, suggesting that the planet formed within a circumbinary disk.