Discover the Webb Space Telescope’s journey to the L2 Lagrange point and how it will observe exoplanets.
Among its extremely ambitious objectives, the Webb Telescope has the mission to characterize the atmosphere of exoplanets. This will be done with the MIRI instrument.
Within the Observatoire de Paris - PSL, LESIA has designed the coronographs of the MIRI instrument. MIRI is the only one of the 4 instruments of the Webb Telescope to be able to observe in the mid-infrared between 5 and 28 microns. This spectral range has two advantages for exoplanets :
- it contains the signature of many molecules (water vapor, ammonia, methane, carbon monoxide...)
- the intensity ratio (or contrast) between a star and a planet is more favorable than at short wavelengths.
Conversely, the angular resolution is reduced and it was thus necessary to adapt the coronagraphic system to achieve the scientific objectives.
The coronagraphs will be used to directly image young giant planets orbiting at several astronomical units from their star.
MIRI also has a low resolution spectrograph to study the composition of the atmospheres of planets transiting in front of their star.
