TESS discovery of a sub-Neptune orbiting a mid-M dwarf TOI-2136. Issue 3 (30th May 2022)

• Record Type: Journal Article
• Authors: Gan, Tianjun; Soubkiou, Abderahmane; Wang, Sharon X; Benkhaldoun, Zouhair; Mao, Shude; Artigau, Étienne; Fouqué, Pascal; Arnold, Luc; Giacalone, Steven; Theissen, Christopher A; Aganze, Christian; Burgasser, Adam; Collins, Karen A; Shporer, Avi; Barkaoui, Khalid; Ghachoui, Mourad; Howell, Steve B; Lamman, Claire; Demangeon, Olivier D S; Burdanov, Artem; Cadieux, Charles; Chouqar, Jamila; Collins, Kevin I; Cook, Neil J; Delrez, Laetitia; Demory, Brice-Olivier; Doyon, René; Dransfield, Georgina; Dressing, Courtney D; Ducrot, Elsa; Fan, Jiahao; Garcia, Lionel; Gill, Holden; Gillon, Michaël; Gnilka, Crystal L; Gómez Maqueo Chew, Yilen; Günther, Maximilian N; Henze, Christopher E; Huang, Chelsea X; Jehin, Emmanuel; Jensen, Eric L N; Lin, Zitao; Manset, Nadine; McCormac, James; Murray, Catriona A; Niraula, Prajwal; Pedersen, Peter P; Pozuelos, Francisco J; Queloz, Didier; Rackham, Benjamin V; Savel, Arjun B; Schanche, Nicole; Schwarz, Richard P; Sebastian, Daniel; Thompson, Samantha; Timmermans, Mathilde; Triaud, Amaury H M J; Vezie, Michael; Wells, Robert D; de Wit, Julien; Ricker, George R; Vanderspek, Roland; Latham, David W; Seager, Sara; Winn, Joshua N; Jenkins, Jon M;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 514:Issue 3(2022)
• Page Start: 4120
• Page End: 4139
• Publication Date: 2022-05-30
• Subjects: planets and satellites: detection -- stars: individual: TIC 336128819 – TOI-2136 -- planetary systems; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac1448
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present the discovery of TOI-2136 b, a sub-Neptune planet transiting a nearby M4.5V-type star every 7.85 d, identified through photometric measurements from the Transiting Exoplanet Survey Satellite ( TESS ) mission. The host star is located 33 pc away with a radius of R * = 0.34 ± 0.02 R⊙, a mass of $0.34\pm 0.02 \, \mathrm{M}_{\odot }$, and an effective temperature of 3342 ± 100 K. We estimate its stellar rotation period to be 75 ± 5 d based on archival long-term photometry. We confirm and characterize the planet based on a series of ground-based multiwavelength photometry, high-angular-resolution imaging observations, and precise radial velocities from Canada–France–Hawaii Telescope (CFHT)/SpectroPolarimètre InfraROUge (SPIRou). Our joint analysis reveals that the planet has a radius of 2.20 ± 0.17 R⊕ and a mass of 6.4 ± 2.4 M⊕ . The mass and radius of TOI-2136 b are consistent with a broad range of compositions, from water-ice to gas-dominated worlds. TOI-2136 b falls close to the radius valley for M dwarfs predicted by thermally driven atmospheric mass-loss models, making it an interesting target for future studies of its interior structure and atmospheric properties.