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Virtual ASD Colloquium

May

25

Probing the Escaping Atmospheres of Exoplanets
Antonija Oklopčić (University of Amsterdam)

Atmospheric escape is an important process in the evolution of exoplanet atmospheres, especially highly irradiated planets orbiting very close to their host stars. However, many aspects of atmospheric escape remain poorly understood, in part due to a limited number of direct observations that have been available until recently. In the last couple of years, transmission spectroscopy in the helium line at 1083 nm has been established as a powerful new probe of the extended and escaping exoplanet atmospheres. These observations allow us to constrain the atmospheric mass loss rates and give us valuable insights into the dynamics of upper atmospheres. In this talk, I will discuss how we can use these observations, together with theoretical models and 3D hydrodynamic simulations of planetary winds, to improve our understanding of the physical processes that drive atmospheric escape. I will also present some of the main challenges involved in our data interpretation, including the uncertainties in the extreme ultraviolet spectra of exoplanet host stars. Finally, I will describe how radiation polarization in the helium 1083 nm line, if observed with the current or next-generation high-resolution spectropolarimeters, could be used to directly probe the magnetic fields of exoplanet atmospheres.

 
Date May 25, 2021
Start/End Time 03:45 PM - 05:00 PM
Website https://science.gsfc.nasa.gov/660/seminars/ASDcolloq/
Contact Knicole Colón
Email Address knicole.colon@nasa.gov
Event Type Seminars/Colloquia
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