TOI-2379 b and TOI-2384 b: two super-Jupiter mass planets transiting low-mass host stars
Butler, R. Paul; Jordán, Andrés; Brahm, Rafael; Bayliss, Daniel; Hobson, Melissa J.; Collins, Karen A.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Crane, Jeffrey D.; Barkaoui, Khalid; Dransfield, Georgina; Gillon, Michaël; Evans, Phil; Bryant, Edward M.; Hartman, Joel D.; Pozuelos, Francisco J.; Jehin, Emmanuël; Ting, Eric B.; Charbonneau, David; Watkins, Cristilyn N.; Schwarz, Richard P.; Murgas, Felipe; Essack, Zahra; Bonfils, Xavier; Teske, Johanna K.; Cointepas, Marion; Almenara, Jose Manuel; Timmermans, Mathilde; Lewis, Hannah M.; Sedaghati, Elyar; Shectman, Steve; Bakos, Gaspar Á.; Wünsche, Anaël
United Kingdom, United States, Chile, Germany, France, Switzerland, Belgium, Spain
Abstract
Short-period gas giant planets have been shown to be significantly rarer for host stars less massive than the Sun. We report the discovery of two transiting giant planets - TOI-2379 b and TOI-2384 b - with low-mass (early M) host stars. Both planets were detected using Transiting Exoplanet Survey Satellite photometry and for both the transit signal was validated using ground-based photometric facilities. We confirm the planetary nature of these companions and measure their masses using radial velocity observations. We find that TOI-2379 b has an orbital period of 5.469 d and a mass and radius of $5.76\pm 0.20$ M$_{J}$ and $1.046\pm 0.023$ R$_{J}$ and TOI-2384 b has an orbital period of 2.136 d and a mass and radius of $1.966\pm 0.059$ M$_{J}$ and $1.025\pm 0.021$ R$_{J}$. TOI-2379 b and TOI-2384 b have the highest and third highest planet-to-star mass ratios, respectively, out of all transiting exoplanets with a low-mass host star, placing them uniquely among the population of known exoplanets and making them highly important pieces of the puzzle for understanding the extremes of giant planet formation.