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

TL;DR

The SPICA coronagraph instrument (SCI) enables direct imaging and spectral analysis of outer exoplanets, including icy giants and gas giants, around nearby stars, aiding understanding of planetary formation and evolution.

Contribution

This paper demonstrates SCI's unique capabilities for detecting and characterizing exoplanets at mid-infrared wavelengths, comparing it with JWST and proposing new insights into planetary system development.

Findings

SCI can detect gas giants down to 1 Jupiter mass around young stars.

SCI can image icy giants like Uranus and Neptune.

SCI offers complementary capabilities to JWST for exoplanet studies.

Abstract

The SPICA coronagraph instrument (SCI) 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. SCI also allows to characterizing those planets of less than 1 Gyr by spectroscopic observations to reveal the nature of planetary formation and evolution. Focusing on the high sensitivity and high contrast at wavelengths longer than 10 \mu m, we show that SCI also allows us to directly image icy giant planets like Uranus and Neptune as well as gas giant planets around nearby early-type stars. In this paper, we compare the capabilities of SCI and the JWST coronagraphs and also discuss a new approach to answering questions concerning the formation and evolution of planetary systems through planet detection with SCI.