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

Abstract

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. 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. 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. We confirm the transit parameters of the planet seen in the literature. We find that a resonant $ $ 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 $2 upper limit of $0.51$ on its Bond albedo, and determine the geometric albedo at $0.34 uncertainty). 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.