WASP-64b and WASP-72b: two new transiting highly irradiated giant planets

TL;DR

This paper reports the discovery of two new highly irradiated hot Jupiters, WASP-64b and WASP-72b, orbiting bright stars, with detailed measurements of their physical and orbital parameters.

Contribution

The paper presents the first discovery and characterization of two new transiting giant exoplanets with high irradiation levels from the WASP survey.

Findings

WASP-64b is a hot Jupiter with mass 1.27 M_Jup and radius 1.27 R_Jup in a 1.57-day orbit.

WASP-72b is a highly irradiated giant with mass 1.46 M_Jup and radius 1.27 R_Jup in a 2.22-day orbit.

Both planets orbit bright stars, making them good targets for further study.

Abstract

We report the discovery by the WASP transit survey of two new highly irradiated giant planets transiting moderately bright stars. WASP-64b is slightly more massive (1.271+-0.068 M_Jup) and larger (1.271+-0.039 R_Jup) than Jupiter, and is in very-short (a=0.02648+-0.00024 AU, P=1.5732918+-0.0000015 days) circular orbit around a V=12.3 G7-type dwarf (1.004+-0.028 M_Sun, 1.058+-0.025 R_Sun, Teff=5500+-150 K). Its size is typical of hot Jupiters with similar masses. WASP-72b has also a mass a bit higher than Jupiter's (1.461-0.056+0.059 M_Jup) and orbits very close (0.03708+-0.00050 AU, P=2.2167421+-0.0000081 days) to a bright (V=9.6) and moderately evolved F7-type star (1.386+-0.055 M_Sun, 1.98+-0.24 R_Sun, Teff=6250+-100 K). Despite its extreme irradiation (about 5.5 10^9 erg/s/cm^2), WASP-72b has a moderate size (1.27+-0.20 R_Jup) that could suggest a significant enrichment in heavy elements. Nevertheless, the errors on its physical parameters are still too high to draw any strong inference on its internal structure or its possible peculiarity.