A Massive Hot Jupiter Orbiting a Metal-rich Early M Star Discovered in the TESS Full-frame Images

October 2023 • 2023AJ....166..165G

Authors • Gan, Tianjun • Cadieux, Charles • Jahandar, Farbod • Vazan, Allona • Wang, Sharon X. • Mao, Shude • Alvarado-Montes, Jaime A. • Lin, D. N. C. • Artigau, Étienne • Cook, Neil J. • Doyon, René • Mann, Andrew W. • Stassun, Keivan G. • Burgasser, Adam J. • Rackham, Benjamin V. • Howell, Steve B. • Collins, Karen A. • Barkaoui, Khalid • Shporer, Avi • de Leon, Jerome • Arnold, Luc • Ricker, George R. • Vanderspek, Roland • Latham, David W. • Seager, Sara • Winn, Joshua N. • Jenkins, Jon M. • Burdanov, Artem • Charbonneau, David • Dransfield, Georgina • Fukui, Akihiko • Furlan, Elise • Gillon, Michaël • Hooton, Matthew J. • Lewis, Hannah M. • Littlefield, Colin • Mireles, Ismael • Narita, Norio • Ormel, Chris W. • Quinn, Samuel N. • Sefako, Ramotholo • Timmermans, Mathilde • Vezie, Michael • de Wit, Julien

Abstract • Observations and statistical studies have shown that giant planets are rare around M dwarfs compared with Sun-like stars. The formation mechanism of these extreme systems has remained under debate for decades. With the help of the TESS mission and ground-based follow-up observations, we report the discovery of TOI-4201b, the most massive and densest hot Jupiter around an M dwarf known so far with a radius of 1.22 ± 0.04 R _J and a mass of 2.48 ± 0.09 M _J, about 5 times heavier than most other giant planets around M dwarfs. It also has the highest planet-to-star mass ratio (q ~ 4 × 10^-3) among such systems. The host star is an early M dwarf with a mass of 0.61 ± 0.02 M _⊙ and a radius of 0.63 ± 0.02 R _⊙. It has significant supersolar iron abundance ([Fe/H] = 0.52 ± 0.08 dex). However, interior structure modeling suggests that its planet TOI-4201b is metal-poor, which challenges the classical core-accretion correlation of stellar-planet metallicity, unless the planet is inflated by additional energy sources. Building on the detection of this planet, we compare the stellar metallicity distribution of four planetary groups: hot/warm Jupiters around G/M dwarfs. We find that hot/warm Jupiters show a similar metallicity dependence around G-type stars. For M-dwarf host stars, the occurrence of hot Jupiters shows a much stronger correlation with iron abundance, while warm Jupiters display a weaker preference, indicating possible different formation histories.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2023AJ....166..165G
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/acf56d/pdf
• PREPRINT http://arxiv.org/abs/2307.07329
• DATA https://archive.gemini.edu/searchform/publication=2023AJ....166..165G
• DATA https://irsa.ipac.caltech.edu/bibdata/2023/G/2023AJ....166..165G.html
• ELECTR https://doi.org/10.3847/1538-3881/acf56d