학술논문
TOI-733 b : A planet in the small-planet radius valley orbiting a Sun-like star
Document Type
Author
Georgieva, Iskra Y.; Persson, Carina M.; Goffo, Elisa; Acuña, Lorena; Aguichine, Artyom; Serrano, Luisa M.; Lam, Kristine W.F.; Gandolfi, Davide; Collins, Karen A.; Howell, Steven B.; Dai, Fei; Fridlund, Malcolm; Korth, Judith; Deleuil, Magali; Barragán, Oscar; Cochran, William D.; Csizmadia, Szilárd; Deeg, Hans J.; Guenther, Eike; Hatzes, Artie P.; Jenkins, Jon M.; Livingston, John; Luque, Rafael; Mousis, Olivier; Osborne, Hannah L.M.; Palle, Enric; Redfield, Seth; Van Eylen, Vincent; Twicken, Joseph D.; Winn, Joshua N.; Alqasim, Ahlam; Collins, Kevin I.; Gnilka, Crystal L.; Latham, David W.; Lewis, Hannah M.; Relles, Howard M.; Ricker, George R.; Rowden, Pamela; Seager, Sara; Shporer, Avi; Tan, Thiam Guan; Vanderburg, Andrew; Vanderspek, Roland
Source
Astronomy and Astrophysics. 674
Subject
Language
English
ISSN
0004-6361
Abstract
We report the discovery of a hot (Teq ≈ 1055 K) planet in the small-planet radius valley that transits the Sun-like star TOI-733. It was discovered as part of the KESPRINT follow-up program of TESS planets carried out with the HARPS spectrograph. TESS photometry from sectors 9 and 36 yields an orbital period of {equation presented} days and a radius of {equation presented}. Multi-dimensional Gaussian process modelling of the radial velocity measurements from HARPS and activity indicators gives a semi-amplitude of K = 2.23 ± 0.26 m s-1, translating into a planet mass of {equation presented}. These parameters imply that the planet is of moderate density ({equation presented}) and place it in the transition region between rocky and volatile-rich planets with H/He-dominated envelopes on the mass-radius diagram. Combining these with stellar parameters and abundances, we calculated planet interior and atmosphere models, which in turn suggest that TOI-733 b has a volatile-enriched, most likely secondary outer envelope, and may represent a highly irradiated ocean world. This is one of only a few such planets around G-type stars that are well characterised.