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

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.