TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf

DOI: 
10.1051/0004-6361/202141587
Publication date: 
24/12/2021
Main author: 
Kossakowski, D.
IAA authors: 
Amado, P. J.;Luque, R.;López, C. Rodríguez
Authors: 
Kossakowski, D.;Kemmer, J.;Bluhm, P.;Stock, S.;Caballero, J. A.;Béjar, V. J. S.;Guillén, C. Cardona;Lodieu, N.;Collins, K. A.;Oshagh, M.;Schlecker, M.;Espinoza, N.;Pallé, E.;Henning, Th.;Kreidberg, L.;Kürster, M.;Amado, P. J.;Anderson, D. R.;Morales, J. C.;Cartwright, S.;Charbonneau, D.;Chaturvedi, P.;Cifuentes, C.;Conti, D. M.;Cortés-Contreras, M.;Dreizler, S.;Galadí-Enríquez, D.;Guerra, P.;Hart, R.;Hellier, C.;Henze, C.;Herrero, E.;Jeffers, S. V.;Jenkins, J. M.;Jensen, E. L. N.;Kaminski, A.;Kielkopf, J. F.;Kunimoto, M.;Lafarga, M.;Latham, D. W.;Lillo-Box, J.;Luque, R.;Molaverdikhani, K.;Montes, D.;Morello, G.;Morgan, E. H.;Nowak, G.;Pavlov, A.;Perger, M.;Quintana, E. V.;Quirrenbach, A.;Reffert, S.;Reiners, A.;Ricker, G.;Ribas, I.;López, C. Rodríguez;Osorio, M. R. Zapatero;Seager, S.;Schöfer, P.;Schweitzer, A.;Trifonov, T.;Vanaverbeke, S.;Vanderspek, R.;West, R.;Winn, J.;Zechmeister, M.
Journal: 
Astronomy and Astrophysics
Publication type: 
Article
Volume: 
656
Pages: 
A124
Abstract: 
We present the discovery of a transiting mini-Neptune around TOI-1201, a relatively bright and moderately young early M dwarf (J ≈ 9.5 mag, ~600-800 Myr) in an equal-mass ~8 arcsecond-wide binary system, using data from the Transiting Exoplanet Survey Satellite, along with follow-up transit observations. With an orbital period of 2.49 d, TOI-1201 b is a warm mini-Neptune with a radius of R<SUB>b</SUB> = 2.415 ± 0.090 R<SUB>⊕</SUB>. This signal is also present in the precise radial velocity measurements from CARMENES, confirming the existence of the planet and providing a planetary mass of M<SUB>b</SUB> = 6.28 ± 0.88 M<SUB>⊕</SUB> and, thus, an estimated bulk density of 2.45<SUB>−0.42</SUB><SUP>+0.48</SUP> g cm<SUP>−3</SUP>. The spectroscopic observations additionally show evidence of a signal with a period of 19 d and a long periodic variation of undetermined origin. In combination with ground-based photometric monitoring from WASP-South and ASAS-SN, we attribute the 19 d signal to the stellar rotation period (P<SUB>rot</SUB> = 19-23 d), although we cannot rule out that the variation seen in photometry belongs to the visually close binary companion. We calculate precise stellar parameters for both TOI-1201 and its companion. The transiting planet is anexcellent target for atmosphere characterization (the transmission spectroscopy metric is 97<SUB>−16</SUB><SUP>+21</SUP>) with the upcoming James Webb Space Telescope. It is also feasible to measure its spin-orbit alignment via the Rossiter-McLaughlin effect using current state-of-the-art spectrographs with submeter per second radial velocity precision. <P />Additional data (i.e., stellar activity indicators) are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/656/A124">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/656/A124</A>
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2021A&A...656A.124K/abstract
ADS Bibcode: 
2021A&A...656A.124K
Keywords: 
techniques: photometric;techniques: radial velocities;planetary systems;stars: individual: TOI-1201;stars: individual: TIC-29 960 110;stars: low-mass;Astrophysics - Earth and Planetary Astrophysics