Models of Stars, Brown Dwarfs and Exoplanets

Within the next few years, GAIA and several instruments aimi ng at imaging extrasolar planets will see first light. In parallel, low mass planets are being searched around red dwarfs which o ffer more favourable conditions, both for radial velocity detection and transit studies, than solar-type stars. Author s of the model atmosphere code which has allowed the detection of water vapour in the atmosp here of Hot Jupiters review recent advancement in modelling the stellar to substel lar transition. The revised solar oxygen abundances and cloud model allow for the first ti me o reproduce the photometric and spectroscopic properties of this transition. Also presented are highlight results of a model atmosphere grid for stars, brown dwarfs an d extrasolar planets.