Seminar Series

27 Apr 2023
Seminars and colloquia
Time
Venue
Dobson Room, AOPP
Speaker(s)

Michael Radica, University of Montreal

Seminar series
AOPP seminar
For more information contact

Towards an Understanding of Impossible Planets

Abstract: One of the lasting legacies of dedicated exoplanet detection missions such as Kepler and TESS is the diversity of worlds that exist outside of our own solar system. From ultra-hot Jupiters to Earth-twins, significant work has been underway for the past two decades to understand the origins and evolution of this plethora of exoplanets; notably via the study of their atmospheres. In particular, two large-scale morphological features of the exoplanet population have captured significant attention in recent years: the small planet radius valley; a bimodal distribution in the sizes of small planets thought to divide rocky super-Earths and gaseous mini-Neptunes, and the hot-Neptune desert; a dearth of planets with masses similar to Neptune and orbital periods less than approximately three days.

With the recent launch of the JWST, and the increasing prominence of ground-based techniques such as high-resolution cross-correlation spectroscopy, our understanding of exoplanets, and in particular, of these curious features of the exoplanet population, is poised to take a significant leap forward. I will present a summary of my work developing and applying a variety of analysis techniques for both ground- and space-based observatories. Beginning with precision radial velocities, and how they can be used to aid our understanding of the origins of the radius valley, I will then present initial atmosphere spectroscopy results from NIRISS/SOSS on the JWST, as well as from the high-resolution spectrograph SPIRou on the CFHT. I will end with an overview of some of my current projects applying these atmosphere spectroscopy techniques to keystone planets within the hot-Neptune desert to better understand how they have come to survive in such inhospitable conditions.

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