論文

2023年3月17日

Direct Imaging Explorations for Companions around Mid–Late M Stars from the Subaru/IRD Strategic Program

The Astronomical Journal
  • 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
  • 全て表示

165
4
開始ページ
162
終了ページ
162
記述言語
掲載種別
研究論文(学術雑誌)
DOI
10.3847/1538-3881/acbf37
出版者・発行元
American Astronomical Society

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 MJup) 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.

リンク情報
DOI
https://doi.org/10.3847/1538-3881/acbf37
URL
https://iopscience.iop.org/article/10.3847/1538-3881/acbf37
URL
https://iopscience.iop.org/article/10.3847/1538-3881/acbf37/pdf
ID情報
  • DOI : 10.3847/1538-3881/acbf37
  • ISSN : 0004-6256
  • eISSN : 1538-3881

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