An extended low-density atmosphere around the Jupiter-sized planet WASP-193 b
Abstract
Gas giants transiting bright nearby stars provide crucial insights into planetary system formation and evolution mechanisms. Most of these planets exhibit certain average characteristics, serving as benchmarks for our understanding of planetary systems. However, outliers like the planet we present in this study, WASP-193b, offer unique opportunities to explore unconventional formation and evolution processes. This planet completes an orbit around its Vmag=12.2 F9 main-sequence host star every 6.25 d. Our analyses found that WASP-193b has a mass of Mp=0.139+/-0.029 MJup and a radius of Rp=1.464+/-0.058 RJup, translating into an extremely low density of rho_p = 0.059+/-0.014 g/cm^3, at least one order of magnitude less than standard gas giants like Jupiter. Typical gas giants such as Jupiter have densities that range between 0.2 and 2 g/cm^3. The combination of its large transit depth (dF~1.4%), its extremely-low density, its high-equilibrium temperature (Teq = 1254+/-31 K), and the infrared brightness of its host star (magnitude Kmag=10.7) makes WASP-193b an exquisite target for characterization by transmission spectroscopy (transmission spectroscopy metric: TSM~600). One single JWST transit observation would yield detailed insights into its atmospheric properties and planetary mass, providing a unique window to explore the mechanisms behind its exceptionally low density and shed light on giant planets' diverse nature.
Cite
@article{arxiv.2307.08350,
title = {An extended low-density atmosphere around the Jupiter-sized planet WASP-193 b},
author = {Khalid Barkaoui and Francisco J. Pozuelos and Coel Hellier and Barry Smalley and Louise D. Nielsen and Prajwal Niraula and Michaël Gillon and Julien de Wit and Simon Müller and Caroline Dorn and Ravit Helled and Emmanuel Jehin and Brice-Olivier Demory and V. Van Grootel and Abderahmane Soubkiou and Mourad Ghachoui and David. R. Anderson and Zouhair Benkhaldoun and Francois Bouchy and Artem Burdanov and Laetitia Delrez and Elsa Ducrot and Lionel Garcia and Abdelhadi Jabiri and Monika Lendl and Pierre F. L. Maxted and Catriona A. Murray and Peter Pihlmann Pedersen and Didier Queloz and Daniel Sebastian and Oliver Turner and Stephane Udry and Mathilde Timmermans and Amaury H. M. J. Triaud and Richard G. West},
journal= {arXiv preprint arXiv:2307.08350},
year = {2024}
}
Comments
10 figures and 35 pages