Three Saturn-mass planets transiting F-type stars revealed with TESS and HARPS: TOI-615b, TOI-622b, and TOI-2641b

Psaridi, Angelica; Bouchy, François; Lendl, Monika; Akinsanmi, Babatunde; Stassun, Keivan G.; Smalley, Barry; Armstrong, David J.; Howard, Saburo; Ulmer-Moll, Solène; Grieves, Nolan; Barkaoui, Khalid; Rodriguez, Joseph E.; Bryant, Edward M.; Suárez, Olga; Guillot, Tristan; Evans, Phil; Attia, Omar; Wittenmyer, Robert A.; Yee, Samuel W.; Collins, Karen A.; Zhou, George; Galland, Franck; Parc, Léna; Udry, Stéphane; Figueira, Pedro; Ziegler, Carl; Mordasini, Christoph; Winn, Joshua N.; Seager, Sara; Jenkins, Jon M.; Twicken, Joseph D.; Brahm, Rafael; Jones, Matías I.; Abe, Lyu; Addison, Brett; Briceño, César; Briegal, Joshua T.; Collins, Kevin I.; Daylan, Tansu; Eigmüller, Phillip; Furesz, Gabor; Guerrero, Natalia M.; Hagelberg, Janis; Heitzmann, Alexis; Hounsell, Rebekah; Huang, Chelsea X.; Krenn, Andreas; Law, Nicholas M.; Mann, Andrew W.; McCormac, James; Mékarnia, Djamel; Mounzer, Dany; Nielsen, Louise D.; Osborn, Ares; Reinarz, Yared; Sefako, Ramotholo R.; Steiner, Michal; Strøm, Pau...

Abstract

While the sample of confirmed exoplanets continues to grow, the population of transiting exoplanets around early-type stars is still limited. These planets allow us to investigate the planet properties and formation pathways over a wide range of stellar masses and study the impact of high irradiation on hot Jupiters orbiting such stars. We report the discovery of TOI-615b, TOI-622b, and TOI-2641b, three Saturn-mass planets transiting main sequence, F-type stars. The planets were identified by the Transiting Exoplanet Survey Satellite (TESS) and confirmed with complementary ground-based and radial velocity observations. TOI-615b is a highly irradiated (similar to 1277 F-circle dot) and bloated Saturn-mass planet (1.69(-0.06)(+0.05) R-Jup and 0.43(-0.08)(+0.09) M-Jup) in a 4.66 day orbit transiting a 6850 K star. TOI-622b has a radius of 0.82(-0.03)(+0.03) R-Jup and a mass of 0.30(-0.08)(+0.07) M-Jup in a 6.40 day orbit. Despite its high insolation flux (similar to 600 F-circle dot), TOI-622b does not show any evidence of radius inflation. TOI-2641b is a 0.39(-0.04)(+0.02) M-Jup planet in a 4.88 day orbit with a grazing transit (b = 1.04(-0.06)(+0.05)) that results in a poorly constrained radius of 1.61(-0.64)(+0.46) R-Jup. Additionally, TOI-615b is considered attractive for atmospheric studies via transmission spectroscopy with ground-based spectrographs and JWST. Future atmospheric and spin-orbit alignment observations are essential since they can provide information on the atmospheric composition, formation, and migration of exoplanets across various stellar types.

• Journal Article Type: Article
• Acceptance Date: May 2, 2023
• Online Publication Date: Jun 30, 2023
• Publication Date: 2023-07
• Deposit Date: Nov 1, 2023
• Publicly Available Date: Nov 2, 2023
• Journal: Astronomy & Astrophysics
• Print ISSN: 0004-6361
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 675
• Pages: A39
• DOI: https://doi.org/10.1051/0004-6361/202346406
• Keywords: Space and Planetary Science; Astronomy and Astrophysics; planets and satellites: individual: TOI-615b / planets and satellites: individual: TOI-622b / stars: early-type / techniques: photometric / techniques: radial velocities / planets and satellites: in