The GAPS programme at TNG

L. TOI-4515 b: An eccentric warm Jupiter orbiting a 1.2 Gyr-old G-star^★

¹ Instituto de Astrofísica de Canarias (IAC), Calle Vía Láctea s/n, 38200 La Laguna, Tenerife, Spain
e-mail: ilariacarleo.astro@gmail.com
² Departamento de Astrofísica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Spain
³ INAF – Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese, Italy
⁴ Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Vicolo dellOsservatorio 3, 35122 Padova, Italy
⁵ INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
⁶ Astronomy Department, Indiana University, Bloomington, IN 47405-7105, USA
⁷ INAF – Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania, Italy
⁸ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
⁹ INAF – Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
¹⁰ Center for Astrophysics – Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
¹¹ Facultad de Ingeniera y Ciencias, Universidad Adolfo Ibáñez, Av. Diagonal las Torres 2640, Peñalolén, Santiago, Chile
¹² Millennium Institute for Astrophysics, Monseñor Sotero Sanz 100, of 10, Providencia, 7500011, Santiago, Chile
¹³ Data Observatory Foundation, DO, Diagonal Las Torres N. 2460, Building E, Peñalokén, Santiago, Chile
¹⁴ SUPA, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
¹⁵ Astrophysics Group, Keele University, Staffs ST5 5BG, UK
¹⁶ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
¹⁷ Center for Data Intensive and Time Domain Astronomy, Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA
¹⁸ Department of Physics & Astronomy, Vanderbilt University, Nashville, TN, USA
¹⁹ Department of Physics, Engineering and Astronomy, Stephen F. Austin State University, 1936 North St, Nacogdoches, TX 75962, USA
²⁰ Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, 38712 Breña Baja, TF, Spain
²¹ INAF – Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monte Porzio Catone, Italy
²² Astrobiology Research Unit, Université de Liège, 19C Allée du Six-Août, 4000 Liège, Belgium
²³ Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
²⁴ INAF – Osservatorio Astronomico di Trieste, via Tiepolo 11, 34143 Trieste, Italy
²⁵ INAF – Osservatorio Astronomico di Brera, Via E. Bianchi 46, 23807 Merate, Italy
²⁶ Cerro Tololo Inter-American Observatory/NSF’s NOIRLab, Casilla 603, La Serena, Chile
²⁷ Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, 10125, Torino, Italy
²⁸ Dipartimento di Fisica, Sapienza, Università di Roma, P.le Aldo Moro, 5, 00185 Rome, Italy
²⁹ NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory (Code 667), Greenbelt, MD 20771, USA
³⁰ Department of Physics and Astronomy, University of New Mexico, 210 Yale Blvd NE, Albuquerque, NM, USA
³¹ Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
³² Observatori de Ca l’Ou, Carrer de dalt 18, Sant Martí Sesgueioles 08282, Barcelona, Spain
³³ Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
³⁴ Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
³⁵ NASA Ames Research Center, Moffett Field, CA 94035 USA
³⁶ Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255, USA
³⁷ NASA Exoplanet Science Institute, IPAC, California Institute of Technology, Pasadena, CA 91125, USA
³⁸ Department of Aeronautics and Astronautics, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
³⁹ Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
⁴⁰ SETI Institute, 339 N Bernardo Ave Suite 200, Mountain View, CA 94043, USA

Received: 9 October 2023
Accepted: 13 November 2023

Abstract

Context. Different theories have been developed to explain the origins and properties of close-in giant planets, but none of them alone can explain all of the properties of the warm Jupiters (WJs, P_orb = 10–200 days). One of the most intriguing characteristics of WJs is that they have a wide range of orbital eccentricities, challenging our understanding of their formation and evolution.

Aims. The investigation of these systems is crucial in order to put constraints on formation and evolution theories. TESS is providing a significant sample of transiting WJs around stars bright enough to allow spectroscopic follow-up studies.

Methods. We carried out a radial velocity (RV) follow-up study of the TESS candidate TOI-4515 b with the high-resolution spectrograph HARPS-N in the context of the GAPS project, the aim of which is to characterize young giant planets, and the TRES and FEROS spectrographs. We then performed a joint analysis of the HARPS-N, TRES, FEROS, and TESS data in order to fully characterize this planetary system.

Results. We find that TOI-4515 b orbits a 1.2 Gyr-old G-star, has an orbital period of P_b = 15.266446 ± 0.000013 days, a mass of M_b = 2.01 ± 0.05 M_J, and a radius of R_b = 1.09 ± 0.04 R_J. We also find an eccentricity of e = 0.46 ± 0.01, placing this planet among the WJs with highly eccentric orbits. As no additional companion has been detected, this high eccentricity might be the consequence of past violent scattering events.