The study of exoplanets is booming. Since the detection of the 1st exoplanet in 1995 by Mr. Mayor and D. Queloz (2019 Nobel Prize in Physics), more than 4000 exoplanets have been detected. The domain is now faced with a new challenge: the characterisation of the atmosphere of exoplanets. Knowledge of the atmosphere brings unique information to constrain the formation and evolution of the exoplanet, its interior, even the presence of biological activity, etc. This characterisation will take a considerable step forward with the launch of two space missions: the JWST in 2021 and the ARIEL mission, entirely dedicated to exoplanet atmospheres, in 2028. The atmosphere is studied from spectroscopic infrared observations; the level of instrumental stability required for these studies is very high (up to 10 ppm over 10 hours).
The JWST was not designed to have the required stability. During his/her thesis the student will determine the stability in flight of the JWST MIRI instrument, to which CEA has made a strong contribution, will compare it with the predicted one and will analyse different methods to improve the stability during data reduction. CEA is also strongly involved in the ARIEL mission (mastery of the main instrument of ARIEL: the AIRS infrared spectrometer; realization and testing of the detection chain). The student will participate in the studies of the instrumental stability (laboratory tests of the detection chain, analysis of results, determination of the best operating modes, system analysis) in order to maximize the instrumental stability upstream to the launch.
Key words : space missions, infrared detectors, exoplanets