Abstract: We will review the observations and the corresponding models of the evaporation of ‘hot Jupiters’. The observations started with the discovery made with HST that the planet orbiting HD209458 has an extended atmosphere of escaping hydrogen. Subsequent observations obtained with STIS and ACS and most recently with COS confirm the escape of the gas. And, even more, oxygen and carbon have been shown to be present at very high altitude in the upper atmosphere. Observations of other targets like HD189733b and WASP-12 show that evaporation is a general phenomenon which could contribute to the evolution of planets orbiting close to their parent stars. To interpret these observations, we developed models to quantify the escape rate from the measured occultation depths. Numerous models have also been published to investigate mechanisms which can lead to the estimated escape rate. In general, the high temperature of the upper atmosphere heated by the far and extreme UV combined with the tidal forces allow a very efficient evaporation of the upper atmosphere. We will review the different models and their implications.

Additional materials: PDF of slides

ExoClimes 2010, Exeter, Wednesday 8^th Sep 2010