THE IMPACT OF MAGNETIC FIELDS ON STELLAR STRUCTURE AND EVOLUTION

Magnetic fields have been detected at the surface of many stars, where they are responsible for various activity phenomena, and presumably they are present also in their deep interior. They channel stellar winds to large distance, thus increasing the loss of angular momentum. In stably stratified radiation zones, they tend to impose uniform rotation, and may thus interfere with the rotational mixing operating in these regions and influence the evolution of the host star. Moreover, certain magnetic configurations are known to be unstable, and they could produce some mixing of their own. We shall discuss these problems in the light of the latest developments.