TOI-2285b: A 1.7 Earth-radius planet near the habitable zone around a nearby M dwarf
Journal article, 2022
We report the discovery of TO1-2285b, a sub-Neptune-sized planet transiting a nearby (42 pc) M dwarf with a period of 27.3 d. We identified the transit signal from the Transiting Exoplanet Survey Satellite photometric data, which we confirmed with ground-based photometric observations using the multiband imagers MuSCAT2 and MuSCAT3. Combining these data with other follow-up observations including high-resolution spectroscopy with the Tillinghast Reflector Echelle Spectrograph, high-resolution imaging with the SPeckle Polarimeter, and radial velocity (RV) measurements with the InfraRed Doppler instrument, we find that the planet has a radius of 1.74 +/- 0.08 R-circle plus, a mass of <19.5 M-circle plus + (95% c.I.), and an insolation flux of 1.54 +/- 0.14 times that of the Earth. Although the planet resides just outside the habitable zone for a rocky planet, if the planet harbors an H2O layer under a hydrogen-rich atmosphere, then liquid water could exist on the surface of the H2O layer depending on the planetary mass and water mass fraction. The bright host star in the near-infrared (K-s = 9.0) makes this planet an excellent target for further RV and atmospheric observations to improve our understanding of the composition, formation, and habitability of sub-Neptune-sized planets.
planets and satellites:detection
planets and satellites: interiors
planets and satellites: individual (TOI-2285b)
techniques: photometric
techniques: radial velocities
Author
Akihiko Fukui
University of Tokyo
Instituto de Astrofísica de Canarias
Tadahiro Kimura
University of Tokyo
Teruyuki Hirano
Astrobiology Center, Japan
Norio Narita
Instituto de Astrofísica de Canarias
University of Tokyo
Astrobiology Center, Japan
Japan Science and Technology Agency
Takanori Kodama
University of Tokyo
Yasunori Hori
National Astronomical Observatory of Japan
Astrobiology Center, Japan
Masahiro Ikoma
National Astronomical Observatory of Japan
Enric Palle
University of La Laguna
Instituto de Astrofísica de Canarias
Felipe Murgas
University of La Laguna
Instituto de Astrofísica de Canarias
Hannu Parviainen
Instituto de Astrofísica de Canarias
University of La Laguna
Kiyoe Kawauchi
Instituto de Astrofísica de Canarias
Mayuko Mori
University of Tokyo
Emma Esparza-Borges
University of La Laguna
Instituto de Astrofísica de Canarias
Allyson Bieryla
Harvard-Smithsonian Center for Astrophysics
Jonathan Irwin
Harvard-Smithsonian Center for Astrophysics
Boris S. Safonov
Moscow State University
Keivan G. Stassun
Fisk University
Vanderbilt University
Leticia Alvarez-Hernandez
University of La Laguna
Victor J. S. Bejar
Instituto de Astrofísica de Canarias
University of La Laguna
Nuria Casasayas-Barris
Leiden University
Guo Chen
Chinese Academy of Sciences
Nicolas Crouzet
European Space Agency (ESA)
Jerome P. de Leon
University of Tokyo
Keisuke Isogai
University of Tokyo
Kyoto University
Taiki Kagetani
University of Tokyo
Peter Klagyivik
German Aerospace Center (DLR)
Judith Korth
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Seiya Kurita
University of Tokyo
Nobuhiko Kusakabe
Astrobiology Center, Japan
John Livingston
University of Tokyo
Rafael Luque
Spanish National Research Council (CSIC)
Alberto Madrigal-Aguado
University of La Laguna
Instituto de Astrofísica de Canarias
Giuseppe Morello
University of La Laguna
Instituto de Astrofísica de Canarias
Taku Nishiumi
The Graduate University for Advanced Studies (SOKENDAI)
Astrobiology Center, Japan
Jaume Orell-Miquel
Instituto de Astrofísica de Canarias
University of La Laguna
Mahmoudreza Oshagh
University of La Laguna
Instituto de Astrofísica de Canarias
Manuel Sanchez-Benavente
Instituto de Astrofísica de Canarias
University of La Laguna
Monika Stangret
University of La Laguna
Instituto de Astrofísica de Canarias
Yuka Terada
Academia Sinica
National Taiwan University
Noriharu Watanabe
University of Tokyo
Yujie Zou
University of Tokyo
Motohide Tamura
National Astronomical Observatory of Japan
University of Tokyo
Astrobiology Center, Japan
Takashi Kurokawa
Tokyo University of Agriculture and Technology
Astrobiology Center, Japan
Masayuki Kuzuhara
Astrobiology Center, Japan
National Astronomical Observatory of Japan
Jun Nishikawa
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Astrobiology Center, Japan
Masashi Omiya
Astrobiology Center, Japan
National Astronomical Observatory of Japan
Sebastien Vievard
National Astronomical Observatory of Japan
Akitoshi Ueda
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Astrobiology Center, Japan
David W. Latham
Harvard-Smithsonian Center for Astrophysics
Samuel N. Quinn
Harvard-Smithsonian Center for Astrophysics
Ivan S. Strakhov
Moscow State University
Alexandr A. Belinski
Moscow State University
Jon M. Jenkins
National Aeronautics and Space Administration (NASA)
George R. Ricker
Massachusetts Institute of Technology (MIT)
Sara Seager
Massachusetts Institute of Technology (MIT)
Roland Vanderspek
Massachusetts Institute of Technology (MIT)
Joshua N. Winn
Princeton University
David Charbonneau
Harvard-Smithsonian Center for Astrophysics
David R. Ciardi
California Institute of Technology (Caltech)
Karen A. Collins
Harvard-Smithsonian Center for Astrophysics
John P. Doty
Noqsi Aerospace Ltd
Etienne Bachelet
Las Cumbres Observatory Global Telescope Network
Daniel Harbeck
Las Cumbres Observatory Global Telescope Network
Publication of the Astronomical Society of Japan
0004-6264 (ISSN) 2053051x (eISSN)
Vol. 74 1 L1-L8Subject Categories (SSIF 2011)
Meteorology and Atmospheric Sciences
Astronomy, Astrophysics and Cosmology
Geophysics
DOI
10.1093/pasj/psab106