Abstract
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 (Ag) 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 m. We derive the first geometric albedo constraints for WASP-50 b and WASP-51 b: Ag < 0.445 and Ag < 0.368, respectively. We find that WASP-43 b and WASP-18 b are both consistent with low geometric albedos (Ag < 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.
Original language | English |
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Pages (from-to) | 3444–3457 |
Number of pages | 14 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 513 |
Issue number | 3 |
Early online date | 9 Apr 2022 |
DOIs | |
Publication status | Published - Jul 2022 |
Bibliographical note
Acknowledgments:M. Blažek, P. Kabáth, and M. Skarka would like to acknowledge a MŠMT INTER-TRANSFER grant number LTT20015. A. Piette acknowledges financial support from the Science and Technology Facilities Council (STFC), UK, towards her doctoral programme. M. Skarka acknowledges the support from OP VVV Postdoc@MUNI (No. CZ.02.2.69/0.0/0.0/16_027/0008360). C. Cáceres acknowledges support by ANID BASAL project FB210003 and ICM Núcleo Milenio de Formación Planetaria, NPF. Based on observations collected at the European Southern Observatory under ESO programme 086.C-0222(B). This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by the NASA’s Science Mission Directorate. We acknowledge IRAF, distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. We thank the editor and the anonymous reviewers for their helpful comments which improved quality of the article.
Keywords
- techniques: photometric
- planets and satellites: atmospheres
- stars: individual: WASP targets
- infrared: planetary systems
- methods: data analysis