Extrasolar planets meet star spots: Sizes of planets, evolution of spots, differential rotation of stars, evaporation of planets ( J. Schmitt, Univ. Hamburg)

Transits of extrasolar planets offer not only the possibility to study the physical properties of

planets, they also provide a new possibility to diagnose the surfaces of active stars, which allows

the study of surface inhomogeneities with unprecedented angular resolution.   I will discuss the

modelling of extrasolar planet transit light curves, and in particular, how the analysis is affected

by star spots and how the derived extrasolar planet parameters depend on the activity state of the spots.  I

will specifically discuss how the transit light curves change due to the presence of star spots and

how this information can be used to construct surface maps of active stars.  A planetary eclipse map of

Corot-2a will be presented.  The potential of transit studies at shorter wavelengths will be discussed and 

furthermore, I will show how high-energy observations constrain the physical properties of extrasolar planets.