Speaker: Sylvie Vauclair (Toulouse)
Title: Atomic diffusion and fingering convection inside stars: the micro-macro connexion.
Abstract: Stars are complex physical laboratories in which various transport processes of the chemical elements do compete. When the stellar gas is stable enough, the chemicals move up or down according to the relative effect of gravity and radiative accelerations (selective radiative transfer). Their motions lead to the accumulation of some elements in specific layers, depletion in other ones. These internal abundance variations are closely related to opacities and they may lead to important opacity modifications inside the star. They can also create inverse mu-gradients, able to trigger fingering convection. I will discuss these effects in connexion with asteroseismology.