Japan Geoscience Union Meeting 2023

Presentation information

[E] Online Poster

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM11] Exoplanet

Thu. May 25, 2023 1:45 PM - 3:15 PM Online Poster Zoom Room (2) (Online Poster)

convener:Takanori Kodama(The university of Tokyo), Shota Notsu(Star and Planet Formation Laboratory, RIKEN Cluster for Pioneering Research), Yui Kawashima(RIKEN), Mayuko Mori(The University of Tokyo)

On-site poster schedule(2023/5/24 17:15-18:45)

1:45 PM - 3:15 PM

[PEM11-P15] Investigation of the possibility of detecting exoplanets and exomoons with the future space interferometers SPICE and LIFE

*Asuka Ota1, Yuka Fujii2, Taro Matsuo1 (1.Nagoya University, 2.National Astronomical Observatory of Japan)

Keywords:exomoon, mid-infrared, far-infrared, space interferometer, direct imaging

Direct detection of exoplanetary spectra puts useful constraints on their atmospheric properties and provides insights into planet formation and evolution. It has been successfully carried out for young self-illuminating Jupiter-like planets on distant orbits. However, direct imaging of low-temperature (∼150 K) exoplanets similar to Jupiter has not been possible because of the limited spatial resolution in the far-infrared domain where these cool planets are brightest. The Space Interferometer for Cosmic Evolution (SPICE), the far-infrared space interferometer project planned for the 2030s, will serve as the first opportunity to image planetary systems with high spatial resolution in the far-infrared domain. Improving the spatial resolution by a factor of 10 or more in the same wavelength will enable direct detection of planetary thermal emissions.

In this study, the detectability of exoplanets in SPICE was investigated. Assuming the SPICE specifications, we found that SPICE will be able to directly detect the planetary thermal emissions with a temperature down to ~190 K around solar-type stars and ~100 K around M-type stars. Among already detected planets, 104 planets, 12 of which were detected using the radial velocity method, could be detected.

We also assessed the detectability of exomoons around these cool Jupiter-like planets through the following two methods: (1) the exomoon eclipses, and (2) using possible absorption lines in exomoon spectra. We found that signals of exomoons would not be possible with SPICE within a reasonable observation time.

We will also discuss the application of Large Interferometer For Exoplanets (LIFE), the mid-infrared interferometer planned for the 2040s, highlighting the effect of different starlight-suppression techniques and the wavelength domain between SPICE and LIFE.