As a post-doctoral researcher, Antoine is interested in transit spectroscopy of exoplanets. He works mainly on the analysis of data from the NIRISS instrument, the Near-InfraRed Imager and Slitless Spectrograph, part of the James Webb Space Telescope. NIRISS allows to analyze the atmosphere of exoplanets by observing their transmission spectrum, which is composed of the light having crossed the atmosphere of these exoplanets. It is then possible to detect the chemical signature of elements such as water vapor, carbon dioxide and potentially to identify biosignatures (chemical signatures of life as we know it) such as oxygen and methane. To achieve such observational feats, all the information contained in the transmission spectra must be extracted in a very precise way. Antoine must therefore use advanced image processing techniques to achieve this.
Antoine also uses the SPIRou instrument, located at the Canada-France-Hawaii Telescope, to study the atmosphere of exoplanets called Hot Jupiters. Their name comes from the fact that they have a similar size and mass to Jupiter, but they are located much closer to their star. This gives them a much higher temperature, above 700˚C. The high-resolution spectroscopic observations obtained with SPIRou allow a better understanding of the chemistry and atmospheric phenomena occurring in the atmosphere of these hot Jupiters.