Wednesday 22 Feb 2023: The origin and evolution of close-in exoplanets
James Owen - Imperial College
Physics building, 4th floor 14:00-15:00
The last decade has taught us exoplanets with radii between 1–4 Earth radii and orbital periods < 100 days are extremely common, with the majority of stars hosting at least one of these planets. The planets were not predicted by our early planet formation models conditioned on explaining the Solar System. Many of these planets are so low density that they only way to explain their current structure is that they host large, but low mass hydrogen dominated atmospheres. One suggestion for the origin of these planets is that the majority were born with hydrogen dominated atmospheres and that a fraction lost these atmospheres due to photo evaporative driven mass-loss. I will discuss the theory behind this evolutionary pathway; how we can use it to extract the properties of the planet’s when they were born and well as discussing the compositional imprints this process leaves behind in the remaining atmospheres.