Constraints on TESS albedos for five hot Jupiters

Martin Blažek , Petr Kabáth , Anjali A. A. Piette , Nikku Madhusudhan , Marek Skarka , Ján Šubjak , David R. Anderson , Henri M. J. Boffin , Claudio C. Cáceres , Neale P. Gibson , Sergio Hoyer (1) , Valentin D. Ivanov , Patricio M. Rojo

1 LAM - Laboratoire d'Astrophysique de Marseille

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 μm. 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 which explain broadband 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.

Keywords: infrared: planetary systems; planets and satellites: atmospheres; stars: individual: WASP targets; software: data analysis; techniques: photometric; Astrophysics - Earth and Planetary Astrophysics

Domains: Sciences of the Universe [physics]

Martin Blažek, Petr Kabáth, Anjali A. A. Piette, Nikku Madhusudhan, Marek Skarka, et al.. Constraints on TESS albedos for five hot Jupiters. Monthly Notices of the Royal Astronomical Society, 2022, ⟨10.1093/mnras/stac992⟩. ⟨insu-03667431⟩