"Unveiling directly imaged systems with the James Webb Space Telescope"

Studying the atmospheres of exoplanets is a major challenge for today's scientific community. Launched in December 2021, the James Webb Space Telescope (JWST) promises a breakthrough in our understanding of exo-systems. Its Mid-IR Instrument MIRI enables the first direct observations at mid-infrared wavelengths with unprecedented sensitivity. Before JWST was operational, direct imaging of exoplanets was limited to near-infrared wavelengths using ground-based instruments, yet it remains the sole method for directly studying the atmospheres of young giant exoplanets at long period. This population of exoplanets plays a crucial role in constraining our understanding of planetary formation and evolution.
In this presentation, I will introduce the challenges and interests of JWST/MIRI observations for directly imaged planets. I will present results from the Exo-MIRI GTO program, among the first observations of exosystems at various wavelengths in the mid-infrared. These observations reveal unexpected features and allows studying exoplanetary atmosphere, providing new constraints on planetary formations. As a conclusion, MIRI cast a new vision of known exoplanetary systems and opens a new field of investigation to characterize young exoplanetary systems.