M dwarf stars; Hot Jupiters; Multiple stars; Binary stars; Transits; Radial velocity; Earth and Planetary Astrophysics; Solar and Stellar Astrophysics
Abstract :
[en] Binary stars are ubiquitous; yet it remains unclear how wide-orbit stellar companions influence the formation of hot Jupiters, particularly around M dwarfs. Here, we first report the discovery of TOI-5628Ab, a giant planet transiting a midtype M dwarf (M* = 0.36 ± 0.02 M<⊙) every 4.34 days, accompanied by an associated white dwarf TOI-5628B (M_WD = 0.59 ± 0.16 M⊙) at a projected distance of about 2500 au. Using TESS, ground-based photometry, and SPIRou radial velocities, we constrain the planet radius to 0.74 ± 0.04 RJ and mass to 0.09 ± 0.04 MJ, with a 3σ upper limit of 0.22 MJ. Building on this system, we further conduct a homogeneous systematic search for comoving stellar companions with projected semimajor axes between 100 and 10,000 au around all M dwarfs with confirmed giant planets with periods smaller than 10 days and radii larger than 0.7 RJ, as well as a group of field M stars with stellar properties similar to the planet sample, based on the stellar kinematics from Gaia DR3. We measure a stellar multiplicity of 34.2% ± 9.5% for M dwarfs hosting short-period giant planets, which is substantially higher than the fraction of 5.3% ± 3.7% for the field M stars by approximately a factor of 6. Our results suggest that wide-orbit stellar companions tend to promote the formation of short-period gas giants around M stars with masses 0.21 ≤ M* ≤ 0.64 M⊙, and high-eccentricity migration may play an important role in producing such systems.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Gan, Tianjun; Department of Astronomy, Westlake University, Hangzhou 310030, Zhejiang Province, People's Republic of China, Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife, Spain, Departamento de Astrofísica, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain
L'Heureux, Alexandrine; Institut Trottier de Recherche sur les Exoplanètes, Département de Physique, Université de Montréal, Montréal, QC H3C 3J7, Canada
Cadieux, Charles; Institut Trottier de Recherche sur les Exoplanètes, Département de Physique, Université de Montréal, Montréal, QC H3C 3J7, Canada, Observatoire de Genève, Département d'Astronomie, Université de Genève, Chemin Pegasi 51, 1290 Versoix, Switzerland
Mao, Shude; Department of Astronomy, Westlake University, Hangzhou 310030, Zhejiang Province, People's Republic of China
Pallé, Enric; Astrophysical Institute of the Canaries, University of La Laguna, Department of Astrophysics
Wang, Sharon X.; Tsinghua University, China
Stassun, Keivan G.; Vanderbilt University, Department of Physics and Astronomy, Fisk University, Tennessee
Howell, Steve B.; NASA Ames Research Center
Rackham, Benjamin V.; MIT, Department of Earth and Planetary Science, MIT, Center for Space Research/Kavli Institute
Grondin, Steffani M.; University of California, San Diego, Center for Astrophysics and Space Science
Barkaoui, Khalid ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Exoplanets in Transit: Identification and Characterization
Arnold, Luc; Canada France Hawaii Telescope (CFHT) Corporation, UAR2208 CNRS-INSU, 65-1238 Mamalahoa Hwy, Kamuela 96743 HI, USA
Artigau, Étienne; Institut Trottier de Recherche sur les Exoplanètes, Département de Physique, Université de Montréal, Montréal, QC H3C 3J7, Canada, Observatoire du Mont-Mégantic, Université de Montréal, Montréal, QC H3C 3J7, Canada
Burdanov, Artem; MIT, Department of Earth and Planetary Science
Burgasser, Adam J.; University of California, San Diego, Center for Astrophysics and Space Science
Caldwell, Douglas A.; NASA Ames Research Center, SETI Institute, California
Ciardi, David R.; Infrared Processing and Analysis Center
Collins, Karen A.; Harvard Smithsonian Center for Astrophysics
Cook, Neil J.; Institut Trottier de Recherche sur les Exoplanètes, Département de Physique, Université de Montréal, Montréal, QC H3C 3J7, Canada
Doyon, René; Institut Trottier de Recherche sur les Exoplanètes, Département de Physique, Université de Montréal, Montréal, QC H3C 3J7, Canada, Observatoire du Mont-Mégantic, Université de Montréal, Montréal, QC H3C 3J7, Canada
Dransfield, Georgina; University of Oxford, Department of Astrophysics, University of Oxford Magdalen College
Fukui, Akihiko; Astrophysical Institute of the Canaries, University of Tokyo, Japan
Gillon, Michaël ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO)
Jehin, Emmanuel ; Université de Liège - ULiège > Unités de recherche interfacultaires > Space sciences, Technologies and Astrophysics Research (STAR)
Murgas, Felipe; Astrophysical Institute of the Canaries, University of La Laguna, Department of Astrophysics
Narita, Norio; Astrophysical Institute of the Canaries, University of Tokyo, Japan, Astrobiology Center, Japan
Noguer, Federico R.; Arizona State University, School of Earth and Space Exploration
Relles, Howard M.; Harvard Smithsonian Center for Astrophysics
Shporer, Avi; MIT, Center for Space Research/Kavli Institute
Simon, Molly N.; Arizona State University, School of Earth and Space Exploration
Theissen, Christopher A.; University of California, San Diego, Center for Astrophysics and Space Science
Timmermans, Mathilde ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Exoplanets in Transit: Identification and Characterization
Triaud, Amaury H. M. J.; University of Birmingham, School of Physics and Astronomy
Zellem, Robert T.; NASA Goddard Space Flight Center, Maryland
