Detection and characterisation of a 106-day transiting Jupiter: TOI-2449 b/NGTS-36 b
Year: 2025
Type: article
Abstract: Context . Only a handful of transiting giant exoplanets with orbital periods longer than 100 days are known. These warm exoplanets are valuable objects, as their radius and mass can be measured and lead to an in-depth characterisation of the planet’s properties. Thanks to low levels of stellar irradiation and large orbital distances, the atmospheric properties and orbital parameters of warm exoplanets remain relatively unaltered by their host star, giving new insights into planetary formation and evolution. Aims . Our aim is to increase the sample of warm giant exoplanets with precise radii and masses. Our goal is to identify suitable candidates in the Transiting Exoplanet Survey Satellite data and perform follow-up observations with ground-based instruments. Methods . We used the Next Generation Transit Survey (NGTS) to detect additional transits of planetary candidates in order to pinpoint their orbital period. We also monitored the target with several high-resolution spectrographs to measure the planetary mass and eccentricity. We studied the planet’s interior composition with a planetary evolution code to determine the planet’s metallicity. Results . We report the discovery of a 106-day period Jupiter-sized planet around the G-type star TOI-2449/NGTS-36. We jointly modelled the photometric and radial velocity data and find that the planet has a mass of 0.70 −0.04 +0.05 M J and a radius of 1.001 ± 0.009 R J . The planetary orbit has a semi-major axis of 0.449 au and is slightly eccentric (e = 0.0098 −0.030 +0.028 ). We detected an additional 3-year signal in the radial velocity data that is likely due to the stellar magnetic cycle. Based on the planetary evolution models considered here, we find that TOI-2449 b/NGTS-36 b contains 11 −5 +6 M ⊕ of heavy elements and has a marginal planet-to-star metal enrichment of 3.3 −1.8 +2.5 . Assuming a Jupiter-like bond albedo, TOI-2449 b/NGTS-36 b has an equilibrium temperature of 400 K and is a good target for understanding nitrogen chemistry in cooler atmospheres.
Source: Astronomy and Astrophysics
Authors: S. Ulmer-Moll, S. Gill, R. Brahm, A. Claringbold, M. Lendl, K. Al Moulla, D. Anderson, M. Battley, D. Bayliss, A. Bonfanti, F. Bouchy, C. Briceño, E. M. Bryant, M. R. Burleigh, K. A. Collins, A. Deline, X. Dumusque, J. Eberhardt, N. Espinoza, B. Falk, J. P. Faria, J. Fernández Fernández, P. Figueira, M. Fridlund, E. Furlan, M. R. Goad, R. F. Goeke, J. Hagelberg, F. Hawthorn, R. Helled, Th. Henning, M. Hobson, S. B. Howell, M. Jafariyazani, J. M. Jenkins, J. S. Jenkins, M. I. Jones, A. Jordán, A. Kendall, N. Law, C. Littlefield, A. W. Mann, J. McCormac, C. Mordasini, M. Moyano, H. Osborn, C. Pezzotti, A. Psaridi, S. N. Quinn, T. Rodel, J. E. Rodriguez, F. Rojas, S. Saha, M. Schlecker, S. Seager, S. G. Sousa, M. Tala Pinto, T. Trifonov, S. Udry, J. I. Vines, G. Viviani, C. A. Watson, P. J. Wheatley, T. G. Wilson, J. N. Winn, G. Zhou, C. Ziegler
Institutions: University of Geneva, University of Bern, Leiden University, Leiden Observatory, University of Warwick, Adolfo Ibáñez University, Millennium Institute of Astrophysics, Data Observatory Foundation, Universidade do Porto, Institute of Astrophysics and Space Sciences, Universidad Católica del Norte, Queen Mary University of London, Austrian Academy of Sciences, Space Research Institute, Cerro Tololo Inter-American Observatory, University College London, University of Leicester, Center for Astrophysics Harvard & Smithsonian, Max Planck Institute for Astronomy, Space Telescope Science Institute, Chalmers University of Technology, California Institute of Technology, NASA Exoplanet Science Institute, Massachusetts Institute of Technology, University of Zurich, Ames Research Center, Search for Extraterrestrial Intelligence, Centro de Astrofísica y Tecnologías Afines, Universidad Diego Portales, European Southern Observatory, European Southern Observatory, University of North Carolina at Chapel Hill, Bay Area Environmental Research Institute, Center for Space and Habitability, University of Liège, Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Queen's University Belfast, Michigan State University, Pontificia Universidad Católica de Chile, University of Arizona, The Ohio State University, Heidelberg University, Sofia University "St. Kliment Ohridski", École Polytechnique Fédérale de Lausanne, Princeton University, University of Southern Queensland, Stephen F. Austin State University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Science Foundation, National Aeronautics and Space Administration, Space Telescope Science Institute, Centres de Recerca de Catalunya, University of Warwick, European Commission, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Generalitat de Catalunya, Korea Astronomy and Space Science Institute, Ministério da Ciência, Tecnologia, Inovações e Comunicações, Agencia Nacional de Investigación y Desarrollo, Ames Research Center, Science Mission Directorate, Science and Technology Facilities Council
Awards: The Next Generation Transit Survey (NGTS): Operations 2019-2022, INSTITUTO MILENIO DE ASTROFISICA, TITANIA: TIme variabiliTy As a New window on exoplanet clImAtes, Warwick Astronomy and Astrophysics Consolidated Grant 2020-2023, Spectroscopy of hot twilights in exoplanetary atmospheres, MSSL Astrophysics Consolidated Grant 2022-25, The Next Generation Transit Survey (NGTS): Operations 2022-2025, G2733421764, G2981143, G3116764410, THE BULK AND ATMOSPHERIC COMPOSITION OF GIANT EXOPLANETS, The Next Generation Transit Survey (NGTS): Deployment and Operations, Resolving and Solving Solar-type Activity with PoET, G4655338613, Queen's University Belfast Astronomy Observation and Theory Consolidated Grant 2023-2026, G5059192377, CONSTRAINING THE ORIGIN OF CLOSE-IN GIANT PLANETS THROUGH A SYSTEMATIC CHARACTERIZATION OF THE POPULATION OF TRANSITING WARM JUPITERS, EXPLOITING CHILEAN INSTRUMENTATION TO DISCOVER EXOPLANETS, G57481727, G5878965429, Warwick Astronomy & Astrophysics Consolidated Grant 2023-2026, G6513613686, Warwick Astronomy and Astrophysics Consolidated Grant 2017-2020, G6686480456, NCCR PlanetS: Origin, evolution and characterisation of planets, G7719629023, G8081747916, G8284171658, G8505061131, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA), G8830025362, PROBING THE FORMATION AND EVOLUTIONARY MECHANISMS WITHIN THE NEPTUNE DESERT
OpenAlex ID: W4415259075