Poster abstract details

Time-resolved spectroscopic observations of rapidly oscillating Ap (roAp) stars show a complex picture of propagating magneto-acoustic pulsation waves, with amplitude and phase strongly changing as a function of atmospheric height. We have recently conducted numerical, non-linear MHD simulations to get an insight into the complex atmospheric dynamics of magnetic pulsators. Here we use the resulting time-dependent atmospheric structure and velocity field to predict line profile variations for roAp stars. These calculations use realistic atmospheric structure, account for vertical chemical stratification and treat line formation in pulsating stellar atmosphere without relying on the simplistic single-layer approximation universally adopted for non-radial pulsators. The new theoretical calculations promise to provide necessary tool to interpret the puzzling complexity of the spectroscopic pulsations in roAp stars.