MASCARA-4 b is a hot Jupiter in a highly-misaligned orbit around a rapidly-rotating A3V star that was observed for 54 days by the Transiting Exoplanet Survey Satellite (\tess). We perform two analyses of MASCARA-4 b using a stellar gravity-darkened model. First, we measure MASCARA-4 b's misaligned orbital configuration by modeling its \tess~photometric light curve. We take advantage of the asymmetry in MASCARA-4 b's transit due to its host star's gravity-darkened surface to measure MASCARA-4 b's true spin-orbit angle to be 104−13∘∘+7∘. We also detect a ∼4σ secondary eclipse at 0.491±0.007 orbital phase, proving that the orbit is slightly eccentric. Second, we model MASCARA-4 b's insolation including gravity-darkening and find that the planet's received XUV flux varies by 4\% throughout its orbit. MASCARA-4 b's short-period, polar orbit suggests that the planet likely underwent dramatic orbital evolution to end up in its present-day configuration and that it receives a varying stellar irradiance that perpetually forces the planet out of thermal equilibrium. These findings make MASCARA-4 b an excellent target for follow-up characterization to better understand orbital evolution and current-day of planets around high-mass stars.
@article{arxiv.1911.05025,
title = {Gravity-Darkening Analysis of Misaligned Hot Jupiter MASCARA-4 b},
author = {John P. Ahlers and Ethan Kruse and Knicole D. Colon and Patrick Dorval and Geert Jan Talens and Ignas Snellen and Simon Albrecht and Gilles Otten and George Ricker and Roland Vanderspek and David Latham and Sara Seager and Joshua Winn and Jon M. Jenkins and Kari Haworth and Scott Cartwright and Robert Morris and Pam Rowden and Peter Tenenbaum and Eric B. TIng},
journal= {arXiv preprint arXiv:1911.05025},
year = {2020}
}