Dr. Ryan Cloutier, Harvard University


Dr. Ryan Cloutier, Harvard University


Date: February 10th, 2022

Time: 10:30 am

Title: Understandingthe Origins of the Galaxy's Most Common Planets Around its Most Common Stars

One of the most important results in the fieldof exoplanet demographics over the past decade has been the discovery thatnature produces two types of planets smaller than Neptune: small, rockysuper-Earths lacking an atmosphere, and larger gas-enveloped terrestrials whoseatmospheres contribute up to a few percent of the planet's total mass. But whatphysical processes are responsible for deciding whether a planet is to be rockyor gas-enveloped? And do these processes differ between planetary systemsaround Sun-like stars versus around the lower mass M dwarf stars that dominatethe galactic stellar inventory? My goal is to elucidate the physical processesthat sculpt the rocky/enveloped transition around M dwarfs in order toestablish whether their planets formed rocky, or if they formed with massiveprimordial envelopes that were lost due to total hydrodynamic escape driven byhigh energy radiation from the host star. I will provide an overview of ourcurrent understanding of these questions and argue that Canadian astronomersare particularly well-positioned to lead future discoveries of the M dwarfexoplanet population using both newly-commissioned and planned facilities onthe ground and in space. Uncovering the formation pathway of the galaxy's mostcommon planets around its most common stars is critical for putting our ownsolar system into a galactic context and will inform the search for lifeoutside of the solar system, as observable biosignatures will only beaccessible in the coming decades for rocky planets that orbit nearby M dwarfs.

Institution: McMaster University

Location: Zoom

Host: Dr. Ralph Pudritz
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