학술논문
TOI-1695 b: A Water World Orbiting an Early M Dwarf in the Planet Radius Valley
Document Type
Working Paper
Author
Cherubim, Collin; Cloutier, Ryan; Charbonneau, David; Wohler, Bill; Stockdale, Chris; Stassun, Keivan G.; Schwarz, Richard P.; Safonov, Boris; Mortier, Annelies; Latham, David W.; Horne, Keith; Haywood, Raphaëlle D.; Gonzales, Erica; Goliguzova, Maria V.; Collins, Karen A.; Ciardi, David R.; Bieryla, Allyson; Belinski, Alexander A.; Watson, Christopher A.; Vanderspek, Rolands; Udry, Stéphane; Sozzetti, Alessandro; Ségransan, Damien; Sasselov, Dimitar; Ricker, George R.; Rice, Ken; Poretti, Ennio; Piotto, Giampaolo; Pepe, Francesco; Molinari, Emilio; Micela, Giuseppina; Mayor, Michel; Lovis, Christophe; López-Morales, Mercedes; Jenkins, Jon M.; Essack, Zahra; Dumusque, Xavier; Doty, John P.; Colón, Knicole D.; Cameron, Andrew Collier; Buchhave, Lars A.
Source
Subject
Language
Abstract
Characterizing the bulk compositions of transiting exoplanets within the M dwarf radius valley offers a unique means to establish whether the radius valley emerges from an atmospheric mass loss process or is imprinted by planet formation itself. We present the confirmation of such a planet orbiting an early M dwarf ($T_{\rm mag} = 11.0294 \pm 0.0074, M_s = 0.513 \pm 0.012\ M_\odot, R_s = 0.515 \pm 0.015\ R_\odot, T_{\rm eff} =3690\pm 50 K$): TOI-1695 b ($P = 3.13$ days, $R_p = 1.90^{+0.16}_{-0.14}\ R_\oplus$). TOI-1695 b's radius and orbital period situate the planet between model predictions from thermally-driven mass loss versus gas depleted formation, offering an important test case for radius valley emergence models around early M dwarfs. We confirm the planetary nature of TOI-1695 b based on five sectors of TESS data and a suite of follow-up observations including 49 precise radial velocity measurements taken with the HARPS-N spectrograph. We measure a planetary mass of $6.36 \pm 1.00\ M_\oplus$, which reveals that TOI-1695 b is inconsistent with a purely terrestrial composition of iron and magnesium silicate, and instead is likely a water-rich planet. Our finding that TOI-1695 b is not terrestrial is inconsistent with the planetary system being sculpted by thermally driven mass loss. We present a statistical analysis of seven well-characterized planets within the M dwarf radius valley demonstrating that a thermally-driven mass loss scenario is unlikely to explain this population.
Comment: 22 pages, 11 figures. Accepted in AJ
Comment: 22 pages, 11 figures. Accepted in AJ