TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet^★

¹ Department of Space, Earth and Environment, Astronomy and Plasma Physics, Chalmers University of Technology, Chalmersplatsen 4, 412 96 Gothenburg, Sweden
e-mail: judith.korth@fysik.lu.se
² Lund Observatory, Division of Astrophysics, Department of Physics, Lund University, Box 43, 22100 Lund, Sweden
³ Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, 10125 Torino, Italy
⁴ Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 25165 Ondřejov, Czech Republic
⁵ Astronomical Institute of Charles University, V Holešovičkách 2, 180 00 Prague, Czech Republic
⁶ ESO, Karl-Schwarzschild-Straße 2, 85748 Garching bei München, Germany
⁷ Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
⁸ Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
⁹ Department of Physics, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran
¹⁰ Instituto de Astrofísica de Canarias (IAC), 38200 La Laguna, Tenerife, Spain
¹¹ Universidad de La Laguna (ULL), Departamento de Astrofísica, 38206 La Laguna, Tenerife, Spain
¹² Institute for Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, 12489 Berlin, Germany
¹³ Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
¹⁴ European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago de Chile, Chile
¹⁵ Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
¹⁶ Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
¹⁷ Astrobiology Research Unit, Université de Liège, Allée du 6 Août 19C, 4000 Liège, Belgium
¹⁸ Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
¹⁹ Institut für Physik, Karl-Franzens Universität Graz, Universitätsplatz 5/II, NAWI Graz, 8010 Graz, Austria
²⁰ Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
²¹ Carnegie Earth and Planets Laboratory, 5241 Broad Branch Road NW, Washington, DC 20015, USA
²² American Association of Variable Star Observers, 49 Bay State Road, Cambridge, MA 02138, USA
²³ George Mason University, 4400 University Drive, Fairfax, VA, 22030 USA
²⁴ The Observatories of the Carnegie Institution for Science, 813 Santa Barbara St., Pasadena, CA 91101, USA
²⁵ Division of Geological and Planetary Sciences, 1200 E California Blvd, Pasadena, CA 91125, USA
²⁶ El Sauce Observatory, Coquimbo Province, Chile
²⁷ Rheinisches Institut für Umweltforschung, Abt. Planetenforschung, an der Universität zu Köln, Aachener Straße 209, 50931 Cologne, Germany
²⁸ Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
²⁹ National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
³⁰ SUPA School of Physics & Astronomy, North Haugh, University of St Andrews, St Andrews KY16 9SS, Scotland, UK
³¹ University of Southern Queensland, Centre for Astrophysics, West Street, Toowoomba, QLD 4350 Australia
³² NASA Ames Research Center, Moffett Field, CA 94035, USA
³³ Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292, USA
³⁴ Department of Astronomy, The Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo, Japan
³⁵ Department of Astronomy & Astrophysics, University of Chicago, Chicago, IL 60637, USA
³⁶ Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
³⁷ Center for Data Intensive and Time Domain Astronomy, Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA
³⁸ Royal Astronomical Society, Burlington House, Piccadilly, London W1J 0BQ, UK
³⁹ Department of Aeronautics and Astronautics, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
⁴⁰ Department of Astronomy, University of Wisconsin-Madison, 475 N Charter St, Madison, WI 53706, USA
⁴¹ Kotizarovci Observatory, Sarsoni 90, 51216 Viskovo, Croatia
⁴² Hazelwood Observatory, Australia
⁴³ Perth Exoplanet Survey Telescope, Perth, Western Australia
⁴⁴ Department of Astronomy, Tsinghua University, Beijing 100084, PR China
⁴⁵ Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA

Received: 28 July 2022
Accepted: 2 May 2023

Abstract

The TOI-1130 is a known planetary system around a K-dwarf consisting of a gas giant planet, TOI-1130 c on an 8.4-day orbit that is accompanied by an inner Neptune-sized planet, TOI-1130 b, with an orbital period of 4.1 days. We collected precise radial velocity (RV) measurements of TOI-1130 with the HARPS and PFS spectrographs as part of our ongoing RV follow-up program. We performed a photodynamical modeling of the HARPS and PFS RVs, along with transit photometry from the Transiting Exoplanet Survey Satellite (TESS) and the TESS Follow-up Observing Program (TFOP). We determined the planet masses and radii of TOI-1130 b and TOI-1130 c to be M_b = 19.28 ± 0.97M_⊕ and R_b = 3.56 ± 0.13 R_⊕, and M_c = 325.59 ± 5.59M_⊕ and R_c = 13.32_−1.41^+1.55 R_⊕, respectively. We have spectroscopically confirmed the existence of TOI-1130 b, which had previously only been validated. We find that the two planets have orbits with small eccentricities in a 2:1 resonant configuration. This is the first known system with a hot Jupiter and an inner lower mass planet locked in a mean-motion resonance. TOI-1130 belongs to the small, yet growing population of hot Jupiters with an inner low-mass planet that poses a challenge to the pathway scenario for hot Jupiter formation. We also detected a linear RV trend that is possibly due to the presence of an outer massive companion.