Abstract

The number of exoplanets newly discovered increases rapidly with time, providing new and sometime puzzling informations about their formation and their structure. In this talk, I will examine our present understanding of the internal structure and evolution of exoplanets.The detection of transiting planets around their parent star allow the determination of their mass and radius, and thus of their mean density. Such valuable information indicates that a significant fraction of these planets are enriched in heavy elements (ice, rocks), as observed in the giant planets of our Solar System. The treatment of heavy materials in planetary interior and the resulting uncertainties on the mass-radius relationship will be discussed. I will also address the case of short-period, strongly irradiated planets and review the different mechanisms, including tidal dissipation, which have been suggested to explain their anomalously large radii.