We present the analysis of TESS optical photometry of WASP-121b, which reveal the phase curve of this transiting ultra-hot Jupiter. Its hotspot is located at the substellar point, showing inefficient heat transport from the dayside (2870 K) to the nightside (< 2200 K) at the altitudes probed by TESS. The TESS eclipse depth, measured at the shortest wavelength to date for WASP-121b, confirms the strong deviation from blackbody planetary emission. Our atmospheric retrieval on the complete emission spectrum supports the presence of a temperature inversion, which can be explained by the presence of VO and possibly TiO and FeH. The strong planetary emission at short wavelengths could arise from an H− continuum.
@article{arxiv.1909.03010,
title = {Optical phase curve of the ultra-hot Jupiter WASP-121b},
author = {V. Bourrier and D. Kitzmann and T. Kuntzer and V. Nascimbeni and M. Lendl and B. Lavie and H. J. Hoeijmakers and L. Pino and D. Ehrenreich and K. Heng and R. Allart and H. M Cegla and X. Dumusque and C. Melo and N. Astudillo-Defru and D. A. Caldwell and M. Cretignier and H. Giles and C. E. Henze and J. Jenkins and C. Lovis and F. Murgas and F. Pepe and G. R. Ricker and M. E. Rose and S. Seager and D. Segransan and A. Suarez-Mascareno and S. Udry and R. Vanderspek and A. Wyttenbach},
journal= {arXiv preprint arXiv:1909.03010},
year = {2020}
}