Convection in stars

Abstract

Convection is one of the most intricate processes studied in stellar astrophysics and has challenged both theorists and observers since the beginnings of astrophysics. But during the last two decades observational data of unprecedented resolution and accuracy have been collected in solar and stellar research which permit a new look at the field. An enormous increase of computer speed now permits solving more complete model equations with more accurate numerical approximations. Modelling and theoretical understanding of convection, however, are lagging behind observational progress and are still wanting.

As a background to the contributions to this session on convection, I first provide an overview on its basic physics and its observational evidence. I point out why astrophysicists have a general interest in improvements of our understanding of stellar convection and then focus on convection in A-stars with their unique combination of convection zones. I summarise how this richness of different manifestations can arise in A-stars, such as convection zones near the surface and in the core, several on top of each other, or some of them depleted by diffusion processes, suppressed by or even creating magnetic fields, suspected to create a chromosphere in some of them, or influenced by binaries, to name just a few. In the last part I will present a few recent results on modelling of convection in A-stars.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html