# Direct detection and spectral characterization of outer exoplanets with the SPICA coronagraph instrument (SCI)

**Authors:** Taro Matsuo, Misato Fukagawa, Takayuki Kotani, Yoichi Itoh, Motohide Tamura, Takao Nakagawa, Keigo Enya, the SCI team  
**arXiv:** [1103.2522](https://arxiv.org/abs/1103.2522)  
**Date:** 2011-03-13  
**Summary page:** https://www.summarizepaper.com/en/paper/1103.2522v1/

## Key points

- The SPICA Coronagraph Instrument (SCI) is used for direct detection and spectral characterization of outer exoplanets.
- It provides high-contrast imaging and moderate resolution spectroscopy at the wavelength range from 3.5 to 27 \mu m.
- SCI will search for gas giant planets down to one Jupiter mass around nearby young (1 Gyr) stars and two Jupiter masses around nearby old (5 Gyr) stars.
- SCI allows for characterizing those planets of less than 1 Gyr by spectroscopic observations to reveal the nature of planetary formation and evolution.
- SCI enables us to directly image icy giant planets like Uranus and Neptune as well as gas giant planets around nearby early-type stars.
- This capability makes it possible to study the atmospheres of these planets in detail, including their composition, temperature structure, and dynamics.
- In comparison with other instruments such as the JWST coronagraphs, SCI has unique advantages in terms of its sensitivity and wavelength coverage.
- A new approach to answering questions concerning the formation and evolution of planetary systems through planet detection with SCI has been proposed which represents a significant step forward in our ability to study exoplanets directly.

## Summary

The SPICA Coronagraph Instrument (SCI) is a powerful tool for direct detection and spectral characterization of outer exoplanets. It provides high-contrast imaging and moderate resolution (R < 200) spectroscopy at the wavelength range from 3.5 to 27 \mu m. Based on the planet evolutional model calculated by Burrows et al. (2003), SCI will search for gas giant planets down to one Jupiter mass around nearby young (1 Gyr) stars and two Jupiter masses around nearby old (5 Gyr) stars. Additionally, SCI allows for characterizing those planets of less than 1 Gyr by spectroscopic observations to reveal the nature of planetary formation and evolution. Focusing on its high sensitivity and high contrast at wavelengths longer than 10 \mu m, SCI also enables us to directly image icy giant planets like Uranus and Neptune as well as gas giant planets around nearby early-type stars. This capability makes it possible to study the atmospheres of these planets in detail, including their composition, temperature structure, and dynamics. In comparison with other instruments such as the JWST coronagraphs, SCI has unique advantages in terms of its sensitivity and wavelength coverage. A new approach to answering questions concerning the formation and evolution of planetary systems through planet detection with SCI has been proposed which represents a significant step forward in our ability to study exoplanets directly, providing valuable insights into their physical properties, formation mechanisms, and evolutionary histories.