Joint HELAS and CoRoT/ESTA Workshop
20-23 November 2006, CAUP, Porto - Portugal

The effects of stellar rotation and magnetism on oscillation frequencies

Daniel Reese

Abstract. In this talk, I will discuss the effects of stellar rotation and magnetism on oscillation frequencies. At slow rotation rates, the perturbative method has shown how rotation lifts mode degeneracy and leads to frequency multiplets. At rapid rotation rates, complete calculations fully taking into account stellar deformation shows that a new organisation of the frequency spectrum appears, in which the centrifugal force plays a dominant role. Stellar magnetism plays an important role on pulsation frequencies both directly and indirectly. Various studies show how magnetism can shift frequencies and play on mode excitation and selection. Magnetism also introduces other types of waves with a different frequency spectrum organisation.