The phase curve of the ultra-hot Jupiter WASP-167b as seen by TESS

¹ Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, HUN-REN, MTA Centre of Excellence, Konkoly-Thege Miklós út 15–17., 1121, Hungary
e-mail: kalman.szilard@csfk.org
² HUN-REN-ELTE Exoplanet Research Group, Szombathely, Szent Imre h. u. 112., 9700, Hungary
³ ELTE Eötvös Loránd University, Doctoral School of Physics, Budapest, Pázmány Péter sétány 1/A, 1117, Hungary
⁴ ELTE Eötvös Loránd University, Gothard Astrophysical Observatory, Szombathely, Szent Imre h. u. 112., 9700, Hungary
⁵ MTA-ELTE Lendület “Momentum” Milky Way Research Group, Szombathely, Szent Imre h. u. 112., 9700, Hungary
⁶ Deutsches Zentrum für Luft- und Raumfahrt, Institute of Planetary Research, Rutherfordstrasse 2, 12489 Berlin, Germany
⁷ HUN-REN-SZTE Stellar Astrophysics Research Group, 6500 Baja, Szegedi út, Kt. 766, Hungary
⁸ ELTE Eötvös Loránd University, Institute of Physics, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
⁹ University of Szeged, Doctoral School of Physics, Dóm tér 9, 6720 Szeged, Hungary
¹⁰ Baja Astronomical Observatory of University of Szeged, 6500 Baja, Szegedi út, Kt. 766, Hungary

Received: 8 December 2023
Accepted: 30 March 2024

Abstract

Context. Ultra-hot Jupiters (UHJs) orbiting pulsating A/F stars represent an important subset of the exoplanetary demographic. They are excellent candidates for the study of exoplanetary atmospheres, and are astrophysical laboratories for the investigation of planet-to- star interactions.

Aims. We analysed the TESS light curve of the WASP-167 system, consisting of an F1V star and a substellar companion on a ~2.02 day orbit.

Methods. We modelled the combination of the ellipsoidal variability and the Doppler beaming to measure the mass of WASP-167b, and the reflection effect to obtain constraints on the geometric albedo, while placing a special emphasis on noise separation. We implemented a basic model to determine the dayside (T_Day), nightside (T_Night), and intrinsic (T_Internal) temperatures of WASP-167b, and put a constraint on its Bond albedo.

Results. We confirm the transit parameters of the planet seen in the literature. We find that a resonant ~2P⁻¹ stellar signal (which may originate from planet-to-star interactions) interferes with the phase curve analysis. After careful and thought-out treatment of this signal, we find M_p = 0.34 ± 0.22 M_J. We measure a dayside temperature of 2790 ± 100 K, classifying WASP-167b as an UHJ. We find a 2σ upper limit of 0.51 on its Bond albedo, and determine the geometric albedo at 0.34 ± 0.11 (1σ uncertainty).

Conclusions. With an occultation depth of 106.8 ± 27.3 ppm in the TESS passband, the UHJ WASP-167b is an excellent target for atmospheric studies, especially those at thermal wavelength ranges, where the stellar pulsations are expected to be less influential.