2022MNRAS.513.3444B

Photometric observations of occultations of transiting exoplanets can place important constraints on the thermal emission and albedos of their atmospheres. We analyse photometric measurements and derive geometric albedo (A_g) constraints for five hot Jupiters observed with TESS in the optical: WASP-18 b, WASP-36 b, WASP-43 b, WASP-50 b, and WASP-51 b. For WASP-43 b, our results are complemented by a VLT/HAWK-I observation in the near-infrared at 2.09\, \mum. We derive the first geometric albedo constraints for WASP-50 b and WASP-51 b: A_g < 0.445 and A_g < 0.368, respectively. We find that WASP-43 b and WASP-18 b are both consistent with low geometric albedos (A_g < 0.16) even though they lie at opposite ends of the hot Jupiter temperature range with equilibrium temperatures of ∼1400 K and ∼2500 K, respectively. We report self-consistent atmospheric models that explain broad-band observations for both planets from TESS, HST, Spitzer, and VLT/HAWK-I. We find that the data of both hot Jupiters can be explained by thermal emission alone and inefficient day-night energy redistribution. The data do not require optical scattering from clouds/hazes, consistent with the low geometric albedos observed.