'Astronomical Society of the Pacific Conference Series'
Abstract
Molecules in the Atmospheres of Extrasolar Planets, proceedings of a conference held at Observatoire de Paris, Paris, France 19-21 November, 2008. ASP Conference Series, Vol. 450. Edited by J.P. Beaulieu, S. Dieteres, and G. Tinetti. San Francisco: Astronomical Society of the Pacific, 2011., p.125The temperature structure and the motions in the atmospheres of cool stars are affected by the underlying convection zone. The radiation hy- drodynamics code CO5BOLD has been developed to simulate (small patches of the) convective surface layers of these stars. Updated opacity tables based on PHOENIX data and a description for the formation, destruction, advective transport, and settling of dust have made the code fit to handle the conditions in brown dwarf atmospheres. Currently, objects from 8500K down to about 900K have been simulated. Recently, incident radiation has been included, allow- ing simulations with conditions found on hot planets. In non-irradiated brown dwarf models we encounter mixing by gravity waves and in the cooler models convection within the clouds. The qualitative effects of incident radiation are surprisingly small, as long as the effective temperature of the object stays well below the dust condensation temperature. Beyond that point, there are no layers where dust could form, anymore