The GAPS Programme at TNG

• Published in: Astronomy and astrophysics (Berlin) Vol. 645
• Main Authors: Carleo, I, Desidera, S, Nardiello, D, Malavolta, L, Lanza, A F, Livingston, J, Locci, D, Marzari, F, Messina, S, Turrini, D, Baratella, M, Borsa, F, V. D’Orazi, Nascimbeni, V, Pinamonti, M, Rainer, M, Alei, E, Bignamini, A, Gratton, R, Micela, G, Montalto, M, Sozzetti, A, Squicciarini, V, Affer, L, Benatti, S, Biazzo, K, Bonomo, A S, Claudi, R, Cosentino, R, Covino, E, Damasso, M, Esposito, M, Fiorenzano, A, Frustagli, G, Giacobbe, P, Harutyunyan, A, Leto, G, Magazzù, A, Maggio, A, Mainella, G, Maldonado, J, Mallonn, M, Mancini, L, Molinari, E, Molinaro, M, Pagano, I, Pedani, M, Piotto, G, Poretti, E, Redfield, S, Scandariato, G
• Format: Journal Article
• Language: English
• Published: Heidelberg EDP Sciences 01.01.2021
• Subjects: Astronomical models; Confidence intervals; Extrasolar planets; Light curve; Orbits; Planet formation; Planetary evolution; Planetary systems; Rotation; Space missions; Transit
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/202039042

Context. Young stars and multi-planet systems are two types of primary objects that allow us to study, understand, and constrain planetary formation and evolution theories. Aims. We validate the physical nature of two Neptune-sized planets transiting TOI-942 (TYC 5909-319-1), a previously unacknowledged young star (50−20+30 Myr) observed by the TESS space mission in Sector 5. Methods. Thanks to a comprehensive stellar characterization, TESS light curve modeling and precise radial-velocity measurements, we validated the planetary nature of the TESS candidate and detected an additional transiting planet in the system on a larger orbit. Results. From photometric and spectroscopic observations we performed an exhaustive stellar characterization and derived the main stellar parameters. TOI-942 is a relatively active K2.5V star (log R′HK = −4.17 ± 0.01) with rotation period Prot = 3.39 ± 0.01 days, a projected rotation velocity v sin i⋆ = 13.8 ± 0.5 km s−1, and a radius of ~0.9 R⊙. We found that the inner planet, TOI-942 b, has an orbital period Pb = 4.3263 ± 0.0011 days, a radius Rb = 4.242−0.313+0.376 R⊕, and a mass upper limit of 16 M⊕ at 1σ confidence level. The outer planet, TOI-942 c, has an orbital period Pc = 10.1605−0.0053+0.0056 days, a radius Rc = 4.793−0.351+0.410 R⊕, and a mass upper limit of 37 M⊕ at 1σ confidence level.