Detection and characterisation of a 106-day transiting Jupiter: TOI-2449 b/NGTS-36 b
Artikel i vetenskaplig tidskrift, 2025
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 MJ and a radius of 1.001 ± 0.009 RJ. 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+6M⊕ 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.
methods: data analysis
planets and satellites: individual: TOI-2449b
planets and satellites: detection
planets and satellites: gaseous planets
Författare
S. Ulmer-Moll
Physics Institute
Université de Genève
Universiteit Leiden
S. Gill
The University of Warwick
Rafael Brahm
Universidad Adolfo Ibanez
Instituto Milenio de Astrofísica
Data Observatory Foundation
A. Claringbold
The University of Warwick
M. Lendl
Université de Genève
K. Al Moulla
Université de Genève
Universidade do Porto
D. Anderson
Universidad Catolica del Norte
M. P. Battley
Université de Genève
Queen Mary University of London
D. Bayliss
The University of Warwick
A. Bonfanti
Institut fur Weltraumforschung
F. Bouchy
Université de Genève
C. Briceño
Cerro Tololo Inter American Observatory
E. Bryant
University College London (UCL)
Matt Burleigh
University Of Leicester
Karen A. Collins
Harvard-Smithsonian Center for Astrophysics
A. Deline
Université de Genève
X. Dumusque
Université de Genève
Jan Eberhardt
Max-Planck-Gesellschaft
Néstor Espinoza
Space Telescope Science Institute (STScI)
B. Falk
Space Telescope Science Institute (STScI)
João Pedro Faria
Université de Genève
J. Fernández Fernández
The University of Warwick
P. Figueira
Université de Genève
Universidade do Porto
Malcolm Fridlund
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Universiteit Leiden
Elise Furlan
National Aeronautics and Space Administration (NASA)
M.R. Goad
University Of Leicester
Robert Goeke
Massachusetts Institute of Technology (MIT)
J. Hagelberg
Université de Genève
F. Hawthorn
The University of Warwick
R. Helled
Universität Zürich
T. Henning
Max-Planck-Gesellschaft
Melissa J. Hobson
Université de Genève
Instituto Milenio de Astrofísica
Max-Planck-Gesellschaft
S.B. Howell
National Aeronautics and Space Administration (NASA)
M. Jafariyazani
SETI Institute
National Aeronautics and Space Administration (NASA)
Jon M. Jenkins
National Aeronautics and Space Administration (NASA)
James S. Jenkins
Centro de Astrofísica y Tecnologías Afines (CATA),
Universidad Diego Portales
M. I. Jones
European Southern Observatory Santiago
Andrés Jordán
Universidad Adolfo Ibanez
Data Observatory Foundation
Instituto Milenio de Astrofísica
Alicia Kendall
University Of Leicester
N. Law
The University of North Carolina System
C. Littlefield
Bay Area Environmental Research Institute (BAER)
National Aeronautics and Space Administration (NASA)
A. Mann
The University of North Carolina System
J. McCormac
The University of Warwick
C. Mordasini
Universität Bern
Physics Institute
M. Moyano
Universidad Catolica del Norte
H. P. Osborn
Physics Institute
C. Pezzotti
Universite de Liège
A. Psaridi
Université de Genève
Consejo Superior de Investigaciones Científicas (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Samuel N. Quinn
Harvard-Smithsonian Center for Astrophysics
T. Rodel
Queen's University Belfast
Joseph E. Rodriguez
Michigan State University
F. Rojas
Instituto Milenio de Astrofísica
Pontificia Universidad Catolica de Chile
S. Saha
Universidad Diego Portales
Centro de Astrofísica y Tecnologías Afines (CATA),
M. Schlecker
University of Arizona
S. Seager
Massachusetts Institute of Technology (MIT)
S.G. Sousa
Universidade do Porto
M. Tala-Pinto
Ohio State University
Instituto Milenio de Astrofísica
Universidad Adolfo Ibanez
T. Trifonov
Sofijski universitet
Landessternwarte Heidelberg-Königstuhl
S. Udry
Université de Genève
José I. Vines
Universidad Catolica del Norte
G. Viviani
Ecole Polytechnique Federale de Lausanne (EPFL)
Christopher Watson
Queen's University Belfast
P. J. Wheatley
The University of Warwick
T.G. Wilson
The University of Warwick
J. N. Winn
Princeton University
George Zhou
University of Southern Queensland
C. Ziegler
Stephen F. Austin State University
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 703 A258Ämneskategorier (SSIF 2025)
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202555168