The Astronomical Journal (Jan 2023)
Direct Imaging Explorations for Companions around Mid–Late M Stars from the Subaru/IRD Strategic Program
- Taichi Uyama,
- Charles Beichman,
- Masayuki Kuzuhara,
- Markus Janson,
- Takayuki Kotani,
- Dimitri Mawet,
- Bun’ei Sato,
- Motohide Tamura,
- Hiroyuki Tako Ishikawa,
- Bryson Cale,
- Thayne Currie,
- Hiroki Harakawa,
- Thomas Henning,
- Teruyuki Hirano,
- Klaus Hodapp,
- Yasunori Hori,
- Masato Ishizuka,
- Shane Jacobson,
- Yui Kasagi,
- Eiichiro Kokubo,
- Mihoko Konishi,
- Tomoyuki Kudo,
- Takashi Kurokawa,
- Nobuhiko Kusakabe,
- Jungmi Kwon,
- Masahiro Machida,
- Takao Nakagawa,
- Norio Narita,
- Jun Nishikawa,
- Masahiro Ogihara,
- Masashi Omiya,
- Takuma Serizawa,
- Akitoshi Ueda,
- Sébastien Vievard,
- Ji Wang
Affiliations
- Taichi Uyama
- ORCiD
- Infrared Processing and Analysis Center, California Institute of Technology , 1200 E. California Boulevard, Pasadena, CA 91125, USA ; [email protected]; NASA Exoplanet Science Institute , Pasadena, CA 91125, USA; National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Charles Beichman
- ORCiD
- Infrared Processing and Analysis Center, California Institute of Technology , 1200 E. California Boulevard, Pasadena, CA 91125, USA ; [email protected]; NASA Exoplanet Science Institute , Pasadena, CA 91125, USA
- Masayuki Kuzuhara
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Markus Janson
- ORCiD
- Department of Astronomy, Stockholm University , AlbaNova University Center, SE-10691, Stockholm, Sweden
- Takayuki Kotani
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Department of Astronomical Science, The Graduate University for Advanced Studies , SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Dimitri Mawet
- ORCiD
- Department of Astronomy, California Institute of Technology , 1200 E. California Boulevard, Pasadena, CA 91125, USA; Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Bun’ei Sato
- ORCiD
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro-ku , Tokyo 152-8551, Japan
- Motohide Tamura
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Department of Astronomy, The University of Tokyo , 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Hiroyuki Tako Ishikawa
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Bryson Cale
- ORCiD
- Infrared Processing and Analysis Center, California Institute of Technology , 1200 E. California Boulevard, Pasadena, CA 91125, USA ; [email protected]; Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Thayne Currie
- ORCiD
- Subaru Telescope, 650 N. Aohoku Place, Hilo, HI 96720, USA; Department of Physics and Astronomy, University of Texas–San Antonio , San Antonio, TX, USA
- Hiroki Harakawa
- ORCiD
- Subaru Telescope, 650 N. Aohoku Place, Hilo, HI 96720, USA
- Thomas Henning
- ORCiD
- Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg, Germany
- Teruyuki Hirano
- ORCiD
- Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Klaus Hodapp
- ORCiD
- University of Hawaii , Institute for Astronomy, 640 N. Aohoku Place, Hilo, HI 96720, USA
- Yasunori Hori
- ORCiD
- Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Masato Ishizuka
- ORCiD
- Department of Astronomy, The University of Tokyo , 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Shane Jacobson
- ORCiD
- University of Hawaii , Institute for Astronomy, 640 N. Aohoku Place, Hilo, HI 96720, USA
- Yui Kasagi
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Department of Astronomical Science, The Graduate University for Advanced Studies , SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Eiichiro Kokubo
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Mihoko Konishi
- ORCiD
- University of Hawaii , Institute for Astronomy, 640 N. Aohoku Place, Hilo, HI 96720, USA
- Tomoyuki Kudo
- ORCiD
- Subaru Telescope, 650 N. Aohoku Place, Hilo, HI 96720, USA
- Takashi Kurokawa
- Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Institute of Engineering, Tokyo University of Agriculture and Technology , 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
- Nobuhiko Kusakabe
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Jungmi Kwon
- ORCiD
- Department of Astronomy, The University of Tokyo , 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Masahiro Machida
- ORCiD
- Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University , Fukuoka, Fukuoka 819-0395, Japan
- Takao Nakagawa
- ORCiD
- Institute of Space and Astronautical Science , Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210, Japan
- Norio Narita
- ORCiD
- Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Komaba Institute for Science, The University of Tokyo , 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; Instituto de Astrofísica de Canarias , E-38205 La Laguna, Tenerife, Spain
- Jun Nishikawa
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Department of Astronomical Science, The Graduate University for Advanced Studies , SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Masahiro Ogihara
- ORCiD
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University , 520 Shengrong Road, Shanghai 201210, People's Republic of China
- Masashi Omiya
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Takuma Serizawa
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Institute of Engineering, Tokyo University of Agriculture and Technology , 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
- Akitoshi Ueda
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Department of Astronomical Science, The Graduate University for Advanced Studies , SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Sébastien Vievard
- ORCiD
- Subaru Telescope, 650 N. Aohoku Place, Hilo, HI 96720, USA
- Ji Wang
- ORCiD
- Department of Astronomy, The Ohio State University , 100 W. 18th Avenue, Columbus, OH 43210, USA
- DOI
- https://doi.org/10.3847/1538-3881/acbf37
- Journal volume & issue
-
Vol. 165,
no. 4
p. 162
Abstract
The Subaru telescope is currently performing a strategic program (SSP) using the high-precision near-infrared (NIR) spectrometer IRD to search for exoplanets around nearby mid/late M dwarfs via radial velocity (RV) monitoring. As part of the observing strategy for the exoplanet survey, signatures of massive companions such as RV trends are used to reduce the priority of those stars. However, this RV information remains useful for studying the stellar multiplicity of nearby M dwarfs. To search for companions around such “deprioritized” M dwarfs, we observed 14 IRD-SSP targets using Keck/NIRC2 with pyramid wave-front sensing at NIR wavelengths, leading to high sensitivity to substellar-mass companions within a few arcseconds. We detected two new companions (LSPM J1002+1459 B and LSPM J2204+1505 B) and two new candidates that are likely companions (LSPM J0825+6902 B and LSPM J1645+0444 B), as well as one known companion. Including two known companions resolved by the IRD fiber injection module camera, we detected seven (four new) companions at projected separations between ∼2 and 20 au in total. A comparison of the colors with the spectral library suggests that LSPM J2204+1505 B and LSPM J0825+6902 B are located at the boundary between late M and early L spectral types. Our deep high-contrast imaging for targets where no bright companions were resolved did not reveal any additional companion candidates. The NIRC2 detection limits could constrain potential substellar-mass companions (∼10–75 M _Jup ) at 10 au or further. The failure with Keck/NIRC2 around the IRD-SSP stars having significant RV trends makes these objects promising targets for further RV monitoring or deeper imaging with the James Webb Space Telescope to search for smaller-mass companions below the NIRC2 detection limits.
Keywords
