Unveiling the Atmospheric Composition of Ultra-hot Giant Exoplanets
Stefan Pelletier
Institut Trottier de recherche sur les exoplanètes / UdeM

Measuring the atmospheric composition of exoplanets and relating this to formation conditions in the protoplanetary disk is a long-standing goal of the planetary science community. However, this requires inferring the abundances of the major elements from which planets form - a notoriously difficult task. Even for Jupiter and Saturn in our own backyard, we only have a handful of abundance measurements, mainly due to their freezing cold temperatures causing most elements to condense out of the upper atmosphere. With temperatures exceeding 2000K, ultra-hot Jupiters offer a unique opportunity to directly probe the composition of giant planets. At such high temperatures, rock-forming species (e.g., Fe, Mg, Si) that would otherwise be effectively impossible to measure on colder planets are vaporized and become accessible to remote sensing. This means that we can measure volatile-to-refractory abundance ratios on ultra-hot Jupiters, which then inform us about the relative amounts of ices and rocks that are accreted during giant planet formation - something that remains unknown even for the Jovian planets in our Solar System.

Date:	Jeudi, 14 septembre 2023
Time:	11:30
Where:	Université de Montréal
	Université de Montréal, Pavillon MIL, Local A-3561