TOI 762 A b and TIC 46432937 b: Two Giant Planets Transiting M-dwarf Stars
Triaud, Amaury H. M. J.; Jordán, Andrés; Brahm, Rafael; Bayliss, Daniel; Howell, Steve B.; Hobson, Melissa J.; Collins, Karen A.; Ricker, George R.; Vanderspek, Roland; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Barkaoui, Khalid; Rapetti, David; Gillon, Michaël; Ducrot, Elsa; Bryant, Edward M.; Hartman, Joel D.; Bakos, Gáspár Á.; Pozuelos, Francisco J.; Charbonneau, David; Furlan, Elise; Bonfils, Xavier; Burke, Christopher J.; Berta-Thompson, Zachory K.; Cointepas, Marion; Jehin, Emmanuel; Almenara, Jose Manuel; Timmermans, Mathilde; Hooton, Matthew J.; Sedaghati, Elyar; Waalkes, William C.; Rodriguez, David R.; Zúñiga-Fernández, Sebastián; Dransfield, George; Pedersen, Peter Pihlmann
United States, United Kingdom, Chile, Switzerland, France, Belgium, Spain
Abstract
We present the discovery of TOI 762 A b and TIC 46432937 b, two giant planets transiting M-dwarf stars. Transits of both systems were first detected from observations by the NASA TESS mission, and the transiting objects are confirmed as planets through high-precision radial velocity observations carried out with Very Large Telescope/ESPRESSO. TOI 762 A b is a warm sub-Saturn with a mass of 0.251 ± 0.042 M J, a radius of 0.744 ± 0.017 R J, and an orbital period of 3.4717 days. It transits a mid-M-dwarf star with a mass of 0.442 ± 0.025 M ☉ and a radius of 0.4250 ± 0.0091 R ☉. The star TOI 762 A has a resolved binary star companion, TOI 762 B, that is separated from TOI 762 A by 3.″2 (∼319 au) and has an estimated mass of 0.227 ± 0.010 M ☉. The planet TIC 46432937 b is a warm super-Jupiter with a mass of 3.20 ± 0.11 M J and radius of 1.188 ± 0.030 R J. The planet's orbital period is P = 1.4404 days, and it undergoes grazing transits of its early M-dwarf host star, which has a mass of 0.563 ± 0.029 M ☉ and a radius of 0.5299 ± 0.0091 R ☉. TIC 46432937 b is one of the highest-mass planets found to date transiting an M-dwarf star. TIC 46432937 b is also a promising target for atmospheric observations, having the highest transmission spectroscopy metric or emission spectroscopy metric value of any known warm super-Jupiter (mass greater than 3.0 M J, equilibrium temperature below 1000 K).