TESS and HARPS reveal two sub-Neptunes around TOI 1062

¹ Observatoire Astronomique de l’Université de Genève, 51 Ch. des Maillettes, Sauverny, 1290 Versoix, Switzerland
e-mail: jonfr17@gmail.com
² Institute for Computational Science, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland
³ Center for Astrobiology (CAB, INTA-CSIC), Dept. de Astrofísica, ESAC campus 28692 Villanueva de la Cañada (Madrid), Spain
⁴ Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
⁵ Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
⁶ Department of Aeronautics and Astronautics, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
⁷ Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
⁸ American Association of Variable Star Observers, 49 Bay State Road, Cambridge, MA 02138, USA
⁹ Patashnick Voorheesville Observatory, Voorheesville, NY 12186, USA
¹⁰ Tsinghua International School, Beijing 100084, PR China
¹¹ Department of Astrophysical Sciences, Princeton University, NJ 08544, USA
¹² NASA Ames Research Center, Moffett Field, CA 94035, USA
¹³ Vanderbilt University, Department of Physics & Astronomy, Nashville, TN 37235, USA
¹⁴ Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
¹⁵ Department of Astronomy, The University of Texas at Austin, Austin, TX 78712, USA
¹⁶ Caltech/IPAC-NExScI, M/S 100-22, 1200 E California Blvd, Pasadena, CA 91125, USA
¹⁷ Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
¹⁸ Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, Porto, Portugal
¹⁹ Department of Physics, University of Warwick, Coventry CV4 7AL, UK
²⁰ Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
²¹ SETI Institute, Mountain View, CA 94043, USA
²² Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
²³ NCCR/PlanetS, Centre for Space & Habitability, University of Bern, Bern, Switzerland
²⁴ Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
²⁵ Leiden Observatory, University of Leiden, PO Box 9513, 2300 RA Leiden, The Netherlands
²⁶ Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, 439 92, Onsala, Sweden
²⁷ Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France
²⁸ European Southern Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile

Received: 27 December 2020
Accepted: 5 May 2021

Abstract

The Transiting Exoplanet Survey Satellite (TESS) mission was designed to perform an all-sky search of planets around bright and nearby stars. Here we report the discovery of two sub-Neptunes orbiting around TOI 1062 (TIC 299799658), a V = 10.25 G9V star observed in the TESS Sectors 1, 13, 27, and 28. We use precise radial velocity observations from HARPS to confirm and characterize these two planets. TOI 1062b has a radius of 2.265_−0.091^+0.096 R_⊕, a mass of 10.15 ± 0.8 M_⊕, and an orbital period of 4.1130 ± 0.0015 days. The second planet is not transiting, has a minimum mass of 9.78_−1.18^+1.26 M_⊕ and is near the 2:1 mean motion resonance with the innermost planet with an orbital period of 7.972_−0.024^+0.018 days. We performed a dynamical analysis to explore the proximity of the system to this resonance, and to attempt further constraining the orbital parameters. The transiting planet has a mean density of 4.85_−0.74^+0.84 g cm⁻³ and an analysis of its internal structure reveals that it is expected to have a small volatile envelope accounting for 0.35% of the mass at most. The star’s brightness and the proximity of the inner planet to what is know as the radius gap make it an interesting candidate for transmission spectroscopy, which could further constrain the composition and internal structure of TOI 1062b.