WASP-30b: a 61 Mjup brown dwarf transiting a V=12, F8 star

TL;DR

This paper reports the discovery and characterization of a 61-Jupiter-mass brown dwarf transiting an F8 star, providing observational confirmation of brown dwarf models and their mass-radius relation.

Contribution

First detection of a transiting brown dwarf with detailed measurements confirming theoretical mass-radius predictions.

Findings

Brown dwarf mass is 61 Jupiter masses.

Radius measured at 0.89 Jupiter radii, matching models.

System age estimated at 1-2 Gyr.

Abstract

We report the discovery of a 61-Jupiter-mass brown dwarf, which transits its F8V host star, WASP-30, every 4.16 days. From a range of age indicators we estimate the system age to be 1-2 Gyr. We derive a radius (0.89 +/- 0.02 RJup) for the companion that is consistent with that predicted (0.914 RJup) by a model of a 1-Gyr-old, non-irradiated brown dwarf with a dusty atmosphere. The location of WASP-30b in the minimum of the mass-radius relation is consistent with the quantitative prediction of Chabrier & Baraffe (2000), thus confirming the theory.