2021-06-23

The most extreme climates in the Universe

speaker: David Ehrenreich

Abstract:

Planets around other stars ―exoplanets― showcase an amazing diversity. This diversity offers many opportunities to study phenomena that do not occur on our Solar System planets, but which may have occured in the past, or could occur in the future. Ultrahot gas giants offer such an opportunity: these are exoplanets so close to their hot stars that they receive thousands of time the insolation of Earth. As such, they are extreme laboratories to study atmospheric physics, chemistry, and climates. They are also well amenable to remote sensing by space-borne and ground-based observations. Trying to learn more about the most extreme climates in the Universe, we could measure stellar dayside temperatures, metallic rains on the nightsides, and atmospheric escape so strong that it may sculpt the whole population of close-in planets. We have also been using these outstanding exoplanets as trojan horses to benchmark characterization techniques that could eventually be applied to smaller, milder planets. I will discuss some of the recent results my group has obtained exploiting data from a range of space-borne and ground-based instruments.