WASP-20b and WASP-28b photometry and RV

WASP-20b is an inflated, Saturn-mass planet (0.31M_Jup_; 1.46R_Jup_) in a 4.9-day, near-aligned (lambda=12.7+/-4.2{deg}) orbit around CD-24 102 (V=10.7; F9). Due to the low density of the planet and the apparent brightness of the host star, WASP-20 is a good target for atmospheric characterisation via transmission spectroscopy.

WASP-28b is an inflated, Jupiter-mass planet (0.91M_Jup_; 1.21R_Jup_) in a 3.4-day, near-aligned (lambda=8+/-18{deg}) orbit around a V=12, F8 star. As intermediate-mass planets in short orbits around aged, cool stars (7^+2^_-1_Gyr and 6000+/-100K for WASP-20; 5^+3^_-2_Gyr and 6100+/-150K for WASP-28), their orbital alignment is consistent with the hypothesis that close-in giant planets are scattered into eccentric orbits with random alignments, which are then circularised and aligned with their stars' spins via tidal dissipation.