Amélie Gressier

Amélie Gressier is a postdoctoral researcher and Trottier Fellow at the Trottier Institute for Research on Exoplanets (IREx) at the Université de Montréal. Her research focuses on the study of exoplanet atmospheres in order to understand the transition between rocky planets like Earth and gas-rich planets like Neptune. She is particularly interested in super-Earths and sub-Neptunes, intermediate-size planets that represent the most common population in the Galaxy but have no equivalent in our Solar System. Using observations from the James Webb Space Telescope (JWST), she analyzes atmospheric spectra to identify the molecules present and to better understand the formation, evolution, and potential habitability of these worlds.

Before joining Montréal, Amélie was a postdoctoral researcher at the Space Telescope Science Institute in Baltimore, where she worked at the center of the scientific exploitation of JWST data. She is a member of several GO and GTO collaborations across Webb instruments and has notably published the NIRSpec spectrum of the super-Earth L98-59 d, revealing absorption from sulfur-bearing species and suggesting possible volcanic activity.

Amélie obtained her PhD in astronomy and astrophysics from the Université Paris-Saclay. Her doctoral research, conducted jointly between the Institut d’Astrophysique de Paris and the Observatoire de Paris, focused on developing methods for the analysis of Hubble Space Telescope data as well as Bayesian inference models for the characterization of exoplanet atmospheres. During her PhD she published the first infrared spectrum of the exoplanet TRAPPIST-1 h, showing that this cold planet could not have retained a hydrogen-rich atmosphere. Before her PhD, Amélie completed a Master’s degree in astrophysics at the Observatoire de Paris. During this work, she studied atmospheric evaporation in hot Jupiters using near-ultraviolet observations from Hubble, detecting atmospheric escape from WASP-121 b and WASP-79 b.

Before moving into astronomy, Amélie trained as an aeronautical engineer at the École Nationale de l’Aviation Civile (ENAC). She worked on the impact of aerosols on radar communications, a project that received the first prize at the European PEGASUS conference in 2019. She also completed an internship at the European Space Agency (ESA) in Rome, where she contributed to the ground segment processing of Sentinel-1 radar satellite imagery for natural disaster monitoring.