Vincent Bourrier
Département d'Astronomie, Université de Genève (Genève, Suisse)
Atmospheric escape is thought to play a major role in sculpting the desert, eroding Neptune-size planets into mini-Neptunes or bare rocky cores. However, it is not clear at what stage of their life evaporation affects different classes of planets. Most studies accounting for long-term atmospheric escape assume early erosion, kindled during formation or after disk-driven migration. Yet, gaseous planets may avoid strong irradiation from their young host star if they migrate long after forming. Late dynamical migration was indeed proposed as one of the processes shaping the desert, but its coupling with atmospheric evolution needs to be explored further.
The study of this coupling is the main objective of the SPICE DUNE(SpectroPhotometric Inquiry of Close-in Exoplanets around the Desert to Understand their Nature and Evolution) project. In this seminar I will present the different chapters of our exploration, highlighting how measurements of orbital architectures and mass loss around the desert informed us about the processes behind its formation, and led us into a new region called the Neptunian savannah.
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris