Disentangling the Kinematics of the Solar Neighborhood to Calibrate the Ages of Stars and Exoplanets

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The recent explosion of exoplanet discoveries drove a revolution in our understanding of their variety, and opened several questions about their formation mechanisms. This research is allowing us to better understand solar system planets and their evolution with a more global view. With the imminent launch of the James Webb Space Telescope (JWST), the community is devising strategies to perform detailed studies of exoplanet atmospheres and identify signatures of life in the form of chemical imbalances. This, however, requires the astrophysics community to improve our understanding of stellar properties, which impact our measurements of their exoplanet properties, and to identify sets of exoplanets with a well-calibrated age to test models of exoplanet formation. I developed the expertise and statistical tools to alleviate the bottleneck of measuring accurate stellar ages in the neighborhood of the Sun. It is possible to determine stellar ages with an unequaled precision by identifying stellar members of loose and coeval young associations. I built the most widely used statistical tools to identify young association members near the Sun, and I use them to lead multiple surveys that aim to uncover the missing members of these young associations, especially those with low masses that are faintest. This allowed me to identify many stars with calibrated ages, some of which are exoplanet hosts. These systems are incredibly important to precisely determine the masses, radii and other properties of stars and their exoplanets. These rare age measurements make it possible to constrain models of stellar evolution and planetary formation with snapshots at specific ages over the evolution of stars and their exoplanets. The research that I lead unveiled several objects with planetary masses that are not in orbit around a star ("planemos"). These planemos are rare; only a dozen are currently known, several of which I identified. However, once they are found, they provide us with age-calibrated planemos, significantly easier to study compared with exoplanets, as we can measure their atmosphere properties with an incredible precision without the nuisance of a bright host star immediately next to them. Planemos are becoming important benchmarks to understand the chemical and physical structure of exoplanet atmospheres, including their cloud properties and how they evolve, both over the timescale of hours and millions of years. I will build a team of graduate students with a focus on equitable hiring methods to further the discovery and characterization of nearby young associations and planemos, and train them to acquire advanced skills of data analysis, coding and statistics. I will foster a culture of collaboration and adaptation to allow them to realize their full potential as highly qualified personnel. This will allow them to initiate fruitful careers, and will further Canada as a leader in the fields of exoplanets and stellar astrophysics.