TOI-1408: Discovery and Photodynamical Modeling of a Small Inner Companion to a Hot Jupiter Revealed by Transit Timing Variations
Journal article, 2024
We report the discovery and characterization of a small planet, TOI-1408 c, on a 2.2 day orbit located interior to a previously known hot Jupiter, TOI-1408 b (P = 4.42 days, M = 1.86 ± 0.02 M Jup, R = 2.4 ± 0.5 R Jup) that exhibits grazing transits. The two planets are near 2:1 period commensurability, resulting in significant transit timing variations (TTVs) for both planets and transit duration variations for the inner planet. The TTV amplitude for TOI-1408 c is 15% of the planet’s orbital period, marking the largest TTV amplitude relative to the orbital period measured to date. Photodynamical modeling of ground-based radial velocity (RV) observations and transit light curves obtained with the Transiting Exoplanet Survey Satellite and ground-based facilities leads to an inner planet radius of 2.22 ± 0.06 R ⊕ and mass of 7.6 ± 0.2 M ⊕ that locates the planet into the sub-Neptune regime. The proximity to the 2:1 period commensurability leads to the libration of the resonant argument of the inner planet. The RV measurements support the existence of a third body with an orbital period of several thousand days. This discovery places the system among the rare systems featuring a hot Jupiter accompanied by an inner low-mass planet.
Author
Judith Korth
Lund University
Priyanka Chaturvedi
Thüringer Landessternwarte Tautenburg
Tata Institute of Fundamental Research
H. Parviainen
Instituto de Astrofísica de Canarias
University of La Laguna
Ilaria Carleo
University of La Laguna
Instituto de Astrofísica de Canarias
Istituto nazionale di astrofisica (INAF)
Michael Endl
College of Natural Sciences
The University of Texas at Austin
E. W. Guenther
Thüringer Landessternwarte Tautenburg
G. Nowak
Nicolaus Copernicus University
University of La Laguna
Instituto de Astrofísica de Canarias
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
P. MacQueen
College of Natural Sciences
A. J. Mustill
Lund University
J. Cabrera
German Aerospace Center (DLR)
William D. Cochran
The University of Texas at Austin
College of Natural Sciences
J. Lillo-Box
Centro de Astrobiologia (CAB)
D. Hobbs
Lund University
F. Murgas
University of La Laguna
Instituto de Astrofísica de Canarias
Michael Greklek-McKeon
California Institute of Technology (Caltech)
Hanna Kellermann
Ludwig Maximilian University of Munich (LMU)
G. Hebrard
Centre national de la recherche scientifique (CNRS)
Institut d 'Astrophysique de Paris
A. Fukui
University of Tokyo
Instituto de Astrofísica de Canarias
Enric Palle
University of La Laguna
Instituto de Astrofísica de Canarias
Jon M. Jenkins
NASA Ames Research Center
J. D. Twicken
NASA Ames Research Center
SETI Institute
Karen A. Collins
Harvard-Smithsonian Center for Astrophysics
Samuel N. Quinn
Harvard-Smithsonian Center for Astrophysics
J. Šubjak
Harvard-Smithsonian Center for Astrophysics
Czech Academy of Sciences
P. G. Beck
Instituto de Astrofísica de Canarias
University of La Laguna
D. Gandolfi
University of Turin
S. Mathur
University of La Laguna
Instituto de Astrofísica de Canarias
H. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
D. W. Latham
Harvard-Smithsonian Center for Astrophysics
Simon Albrecht
Aarhus University
D. Barrado
Centro de Astrobiologia (CAB)
I. Boisse
Centre national de la recherche scientifique (CNRS)
Laboratoire d'Astrophysique de Marseille
Hervé Bouy
Institut Universitaire de France
Laboratoire d'Astrophysique de Bordeaux
X. Delfosse
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
O. Demangeon
University of Porto
R. A. García
University Paris-Saclay
A. Hatzes
Thüringer Landessternwarte Tautenburg
N. Heidari
Institut d 'Astrophysique de Paris
Kai Ikuta
University of Tokyo
Petr Kabath
Czech Academy of Sciences
H. Knutson
California Institute of Technology (Caltech)
J.H. Livingston
The Graduate University for Advanced Studies (SOKENDAI)
National Institutes of Natural Sciences
National Astronomical Observatory of Japan
E. Martioli
Institut d 'Astrophysique de Paris
Laboratorio Nacional de Astrofisica, Itajuba
M. Morales-Calderon
Centro de Astrobiologia (CAB)
Giuseppe Morello
Institute of Astrophysics of Andalusia (IAA)
Instituto de Astrofísica de Canarias
Norio Narita
University of Tokyo
National Institutes of Natural Sciences
Instituto de Astrofísica de Canarias
J. Orell-Miquel
University of La Laguna
Instituto de Astrofísica de Canarias
H. L.M. Osborne
European Southern Observatory (ESO)
University College London (UCL)
Dinil B. Palakkatharappil
University Paris-Saclay
Viktoria Pinter
Nordic Optical Telescope
University of Craiova
S. Redfield
Wesleyan University
Howard M. Relles
Harvard-Smithsonian Center for Astrophysics
R. Schwarz
Harvard-Smithsonian Center for Astrophysics
S. Seager
Massachusetts Institute of Technology (MIT)
Massachusetts Institute of Technology
Avi Shporer
Massachusetts Institute of Technology (MIT)
Marek Skarka
Masaryk University
Czech Academy of Sciences
G. Srdoc
Kotizarovci Observatory
M. Stangret
Istituto nazionale di astrofisica (INAF)
Luis Thomas
Max Planck Society
Ludwig Maximilian University of Munich (LMU)
Vincent Van Eylen
University College London (UCL)
Noriharu Watanabe
University of Tokyo
J. N. Winn
Princeton University
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 971 2 L28Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.3847/2041-8213/ad65fd