A Cold and Super-Puffy Planet on a Polar Orbit
Juan I. Espinoza-Retamal, Rafael Brahm, Cristobal Petrovich, Andrés Jordán, Thomas Henning, Trifon Trifonov, Joshua N. Winn, Erika Rea, Maximilian N. Günther, Abdelkrim Agabi, Philippe Bendjoya, Hareesh Bhaskar, François Bouchy, Márcio Catelan, Carolina Charalambous, Vincent Deloupy, George Dransfield, Jan Eberhardt, Néstor Espinoza, Alix V. Freckelton, Tristan Guillot, Melissa J. Hobson, Matías I. Jones, Monika Lendl, Djamel Mekarnia, Diego J. Muñoz, Louise D. Nielsen, Felipe I. Rojas, François-Xavier Schmider, Elyar Sedaghati, Guðmundur Stefánsson, Stephanie Striegel, Olga Suarez, Marcelo Tala Pinto, Mathilde Timmermans, Amaury H. M. J. Triaud, Stéphane Udry, Solène Ulmer-Moll, Carl Ziegler
公開日: 2025/9/30
Abstract
We report the discovery of TOI-4507 b, a transiting sub-Saturn with a density $<0.3$ g/cm$^3$ on a 105-day polar orbit around a $700$ Myr old F star. The transits were detected using data from TESS as well as the Antarctic telescope ASTEP. A joint analysis of the light curves and radial velocities from HARPS, FEROS, and CORALIE confirmed the planetary nature of the signal by limiting the mass to be below $30\,M_\oplus$ at $95\%$ confidence. The radial velocities also exhibit the Rossiter-McLaughlin effect and imply that the star's equatorial plane is tilted by $82.0_{-2.4}^{+2.6}$ deg with respect to the planet's orbital plane. With these characteristics, TOI-4507 b is one of longest-period planets for which the stellar obliquity has been measured, and is among the longest-period and youngest ''super-puff'' planets yet discovered.