The Astronomical Journal (Jan 2023)
TOI-1695 b: A Water World Orbiting an Early-M Dwarf in the Planet Radius Valley
- Collin Cherubim,
- Ryan Cloutier,
- David Charbonneau,
- Chris Stockdale,
- Keivan G. Stassun,
- Richard P. Schwarz,
- Boris Safonov,
- Annelies Mortier,
- Pablo Lewin,
- David W. Latham,
- Keith Horne,
- Raphaëlle D. Haywood,
- Erica Gonzales,
- Maria V. Goliguzova,
- Karen A. Collins,
- David R. Ciardi,
- Allyson Bieryla,
- Alexandre A. Belinski,
- Bill Wohler,
- Christopher A. Watson,
- Roland Vanderspek,
- Stéphane Udry,
- Alessandro Sozzetti,
- Damien Ségransan,
- Dimitar Sasselov,
- George R. Ricker,
- Ken Rice,
- Ennio Poretti,
- Giampaolo Piotto,
- Francesco Pepe,
- Emilio Molinari,
- Giuseppina Micela,
- Michel Mayor,
- Christophe Lovis,
- Mercedes López-Morales,
- Jon M. Jenkins,
- Zahra Essack,
- Xavier Dumusque,
- John P. Doty,
- Knicole D. Colón,
- Andrew Collier Cameron,
- Lars A. Buchhave
Affiliations
- Collin Cherubim
- ORCiD
- Earth and Planetary Science, Harvard University , 20 Oxford Street, Cambridge, MA, 02138, USA ; [email protected]; Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- Ryan Cloutier
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA; Dept. of Physics & Astronomy, McMaster University , 1280 Main Street West, Hamilton, ON, L8S 4L8, Canada
- David Charbonneau
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- Chris Stockdale
- ORCiD
- Hazelwood Observatory , Australia
- Keivan G. Stassun
- ORCiD
- Department of Physics and Astronomy, Vanderbilt University , Nashville, TN, 37235, USA
- Richard P. Schwarz
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- Boris Safonov
- ORCiD
- Sternberg Astronomical Institute, Lomonosov Moscow State University , 119992, Moscow, Russia, Universitetskii prospekt, 13, Russia
- Annelies Mortier
- ORCiD
- KICC & Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, UK; School of Physics & Astronomy, University of Birmingham , Edgbaston, Birmingham, B15 2TT, UK
- Pablo Lewin
- ORCiD
- The Maury Lewin Astronomical Observatory , Glendora, CA, 91741, USA
- David W. Latham
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- Keith Horne
- ORCiD
- SUPA School of Physics and Astronomy, University of St. Andrews , Fife, KY16 9SS, Scotland, UK
- Raphaëlle D. Haywood
- ORCiD
- Astrophysics Group, University of Exeter , Exeter, EX4 2QL, UK
- Erica Gonzales
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA, 95064, USA
- Maria V. Goliguzova
- Sternberg Astronomical Institute, Lomonosov Moscow State University , 119992, Moscow, Russia, Universitetskii prospekt, 13, Russia
- Karen A. Collins
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- David R. Ciardi
- ORCiD
- Caltech/IPAC , 1200 E. California Boulevard Pasadena, CA, 91125, USA
- Allyson Bieryla
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- Alexandre A. Belinski
- ORCiD
- Sternberg Astronomical Institute, Lomonosov Moscow State University , 119992, Moscow, Russia, Universitetskii prospekt, 13, Russia
- Bill Wohler
- ORCiD
- SETI Institute , Mountain View, CA, 94043, USA; NASA Ames Research Center , Moffett Field, CA, 94035, USA
- Christopher A. Watson
- ORCiD
- Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast , Belfast, BT7 1NN, UK
- Roland Vanderspek
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA, 02139, USA; Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA, 02139, USA
- Stéphane Udry
- ORCiD
- Observatoire Astronomique de l’Université de Genève , Chemin Pegasi 51, 1290 Versoix, Switzerland
- Alessandro Sozzetti
- ORCiD
- INAF—Osservatorio Astrofisico di Torino , Strada Osservatorio 20, Pino Torinese (To) I-10025, Italy
- Damien Ségransan
- ORCiD
- Observatoire Astronomique de l’Université de Genève , 51 chemin des Maillettes, 1290 Versoix, Switzerland
- Dimitar Sasselov
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- George R. Ricker
- ORCiD
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA, 02139, USA; Department of Physics, Massachusetts Institute of Technology , Cambridge, MA, 02139, USA
- Ken Rice
- ORCiD
- SUPA, Institute for Astronomy, University of Edinburgh , Blackford Hill, Edinburgh, EH9 3HJ, Scotland, UK; Centre for Exoplanet Science, University of Edinburgh , Edinburgh, UK
- Ennio Poretti
- ORCiD
- Fundación Galileo Galilei-INAF , Rambla José Ana Fernandez Pérez 7, E-38712 Breña Baja, TF, Spain; INAF-Osservatorio Astronomico di Brera , via E. Bianchi 46, I-23807 Merate (LC), Italy
- Giampaolo Piotto
- ORCiD
- Dip. di Fisica e Astronomia Galileo Galilei—Università di Padova , Vicolo dell’Osservatorio 2, I-35122, Padova, Italy
- Francesco Pepe
- Observatoire Astronomique de l’Université de Genève , 51 chemin des Maillettes, 1290 Versoix, Switzerland
- Emilio Molinari
- ORCiD
- INAF—Osservatorio Astronomico di Cagliari , via della Scienza 5, I-09047, Selargius, Italy
- Giuseppina Micela
- ORCiD
- INAF—Osservatorio Astronomico di Palermo , Piazza del Parlamento 1, I-90134 Palermo, Italy
- Michel Mayor
- ORCiD
- Observatoire Astronomique de l’Université de Genève , 51 chemin des Maillettes, 1290 Versoix, Switzerland
- Christophe Lovis
- Observatoire Astronomique de l’Université de Genève , 51 chemin des Maillettes, 1290 Versoix, Switzerland
- Mercedes López-Morales
- ORCiD
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- Jon M. Jenkins
- ORCiD
- NASA Ames Research Center , Moffett Field, CA, 94035, USA
- Zahra Essack
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA, 02139, USA; Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA, 02139, USA
- Xavier Dumusque
- ORCiD
- Observatoire Astronomique de l’Université de Genève , 51 chemin des Maillettes, 1290 Versoix, Switzerland
- John P. Doty
- ORCiD
- Noqsi Aerospace Ltd. , 15 Blanchard Avenue, Billerica, MA, 01821, USA
- Knicole D. Colón
- ORCiD
- NASA Goddard Space Flight Center , Greenbelt, MD, 20771, USA
- Andrew Collier Cameron
- ORCiD
- SUPA School of Physics and Astronomy, University of St. Andrews , Fife, KY16 9SS, Scotland, UK
- Lars A. Buchhave
- ORCiD
- DTU Space, National Space Institute, Technical University of Denmark , Elektrovej 328, DK-2800 Kgs. Lyngby, Denmark
- DOI
- https://doi.org/10.3847/1538-3881/acbdfd
- Journal volume & issue
-
Vol. 165,
no. 4
p. 167
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 _mag = 11.0294 ± 0.0074, M _s = 0.513 ± 0.012 M _⊙ , R _s = 0.515 ± 0.015 R _⊙ , and T _eff = 3690 ± 50 K): TOI-1695 b ( P = 3.13 days and ${R}_{p}={1.90}_{-0.14}^{+0.16}\ {R}_{\oplus }$ ). 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 ± 1.00 M _⊕ , 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.
Keywords
- Exoplanets
- Exoplanet formation
- Planet formation
- Exoplanet evolution
- M dwarf stars
- Exoplanet atmospheric evolution
