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: radial velocities

techniques: photometric

Author

Akihiko Fukui

University of Tokyo

Instituto de Astrofísica de Canarias

Tadahiro Kimura

University of Tokyo

Teruyuki Hirano

Astrobiology Center, Japan

Norio Narita

University of Tokyo

Astrobiology Center, Japan

Japan Science and Technology Agency

Instituto de Astrofísica de Canarias

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

Instituto de Astrofísica de Canarias

University of La Laguna

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

Instituto de Astrofísica de Canarias

University of La Laguna

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 Research and Technology Centre (ESA ESTEC)

Jerome P. de Leon

University of Tokyo

Keisuke Isogai

Kyoto University

University of Tokyo

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

Institute of Astrophysics of Andalusia (IAA)

Alberto Madrigal-Aguado

Instituto de Astrofísica de Canarias

University of La Laguna

Giuseppe Morello

Instituto de Astrofísica de Canarias

University of La Laguna

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

Instituto de Astrofísica de Canarias

University of La Laguna

Manuel Sanchez-Benavente

University of La Laguna

Instituto de Astrofísica de Canarias

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

Astrobiology Center, Japan

University of Tokyo

Takashi Kurokawa

Tokyo University of Agriculture and Technology

Astrobiology Center, Japan

Masayuki Kuzuhara

National Astronomical Observatory of Japan

Astrobiology Center, Japan

Jun Nishikawa

Astrobiology Center, Japan

The Graduate University for Advanced Studies (SOKENDAI)

National Astronomical Observatory of 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)

Astrobiology Center, Japan

National Astronomical Observatory of 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

NASA Ames Research Center

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-L8

Subject Categories

Meteorology and Atmospheric Sciences

Astronomy, Astrophysics and Cosmology

Geophysics

DOI

10.1093/pasj/psab106

More information

Latest update

3/3/2022 1