TOI-2285b: A 1.7 Earth-radius planet near the habitable zone around a nearby M dwarf-Reference-Cited by-同舟云学术

TOI-2285b: A 1.7 Earth-radius planet near the habitable zone around a nearby M dwarf

Published:2021-12-05 Issue:1 Volume:74 Page:L1-L8
ISSN:0004-6264
Container-title:Publications of the Astronomical Society of Japan
language:en
Short-container-title:

Author:

Fukui Akihiko¹²^ORCID,Kimura Tadahiro³,Hirano Teruyuki⁴^ORCID,Narita Norio¹²⁴⁵,Kodama Takanori¹,Hori Yasunori⁴⁶,Ikoma Masahiro⁶,Pallé Enric²⁷,Murgas Felipe²⁷,Parviainen Hannu²⁷^ORCID,Kawauchi Kiyoe²,Mori Mayuko⁸,Esparza-Borges Emma²⁷^ORCID,Bieryla Allyson⁹,Irwin Jonathan⁹,Safonov Boris S¹⁰,Stassun Keivan G¹¹¹²^ORCID,Alvarez-Hernandez Leticia⁷,Béjar Víctor J S²⁷,Casasayas-Barris Núria¹³,Chen Guo¹⁴^ORCID,Crouzet Nicolas¹⁵,de Leon Jerome P⁸,Isogai Keisuke¹⁶¹⁷,Kagetani Taiki¹⁷^ORCID,Klagyivik Peter¹⁸,Korth Judith¹⁹,Kurita Seiya³,Kusakabe Nobuhiko⁴,Livingston John⁸^ORCID,Luque Rafael²⁰^ORCID,Madrigal-Aguado Alberto²⁷,Morello Giuseppe²⁷,Nishiumi Taku⁴²¹,Orell-Miquel Jaume²⁷,Oshagh Mahmoudreza²⁷,Sánchez-Benavente Manuel²⁷,Stangret Monika²⁷,Terada Yuka²²²³,Watanabe Noriharu¹⁷,Zou Yujie¹⁷^ORCID,Tamura Motohide⁴⁶⁸,Kurokawa Takashi⁴²⁴,Kuzuhara Masayuki⁴⁶,Nishikawa Jun⁴⁶²¹,Omiya Masashi⁴⁶,Vievard Sébastien²⁵,Ueda Akitoshi⁴⁶²¹,Latham David W⁹,Quinn Samuel N⁹,Strakhov Ivan S¹⁰,Belinski Alexandr A¹⁰,Jenkins Jon M²⁶,Ricker George R²⁷,Seager Sara²⁷²⁸²⁹,Vanderspek Roland²⁷,Winn Joshua N³⁰,Charbonneau David⁹,Ciardi David R³¹,Collins Karen A⁹,Doty John P³²,Bachelet Etienne³³,Harbeck Daniel³³

Affiliation:

1. Komaba Institute for Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan

2. Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife, Spain

3. Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

4. Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan

5. Japan Science and Technology Agency, PRESTO, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan

6. National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, 181-8588 Tokyo, Japan

7. Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain

8. Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

9. Center for Astrophysics, Harvard and Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA

10. Sternberg Astronomical Institute, M.V. Lomonosov Moscow State University, 13, Universitetskij pr., 119234, Moscow, Russia

11. Department of Physics and Astronomy, Vanderbilt University, 6301 Stevenson Center Ln., Nashville, TN 37235, USA

12. Department of Physics, Fisk University, 1000 17th Avenue North, Nashville, TN 37208, USA

13. Leiden Observatory, Leiden University, Postbus 9513, 2300 RA Leiden, the Netherlands

14. CAS Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210023, China

15. European Space Agency (ESA), European Space Research and Technology Centre (ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, the Netherlands

16. Okayama Observatory, Kyoto University, 3037-5 Honjo, Kamogatacho, Asakuchi, Okayama 719-0232, Japan

17. Department of Multi-Disciplinary Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan

18. Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489, Berlin, Germany

19. Department of Space, Earth and Environment, Astronomy and Plasma Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden

20. Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía s/n, 18008 Granada, Spain

21. Department of Astronomical Science, The Graduated University for Advanced Studies, SOKENDAI, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588, Japan

22. Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan

23. Department of Astrophysics, National Taiwan University, Taipei 10617, Taiwan

24. Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo, 184-8588, Japan

25. Subaru Telescope, 650 N. Aohoku Place, Hilo, HI 96720, USA

26. NASA Ames Research Center, Moffett Field, CA 94035, USA

27. Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA

28. Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA

29. Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA

30. Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08540, USA

31. Caltech/IPAC-NASA Exoplanet Science Institute, 770 S. Wilson Avenue, Pasadena, CA 91106, USA

32. Noqsi Aerospace Ltd., 15 Blanchard Avenue, Billerica, MA 01821, USA

33. Las Cumbres Observatory, 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575, USA

Abstract

Abstract We report the discovery of TOI-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 $1.74 \pm 0.08\, R_\oplus$, a mass of $\lt \!\!19.5\,M_\oplus$ ($95\%$ c.l.), 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 (Ks = 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.

Funder

California Institute of Technology

JSPS

JST PRESTO

National Institutes of Natural Sciences

Spanish Ministry of Economics and Competitiveness

Ministry of Science and Higher Education of the Russian Federation

European Research Council

Horizon 2020

Marie Skłodowska-Curie

Swedish National Space Agency

Ministerio de Ciencia e Innovación