The Physics of Mass Loss from Agb-Stars

Four mechanisms that have been proposed for the mass loss from Asymptotic Giant Branch stars are discussed. These are radiative driving of the dust, radial pulsations, Alfven wave driven winds and sound wave driven winds. Radial pulsations can drive the observed mass loss if dust forms sufficiently close to the star. Sound waves can drive the observed winds, even if the dust forms a great distance from the star. A crucial observation for deciding between these two mechanisms is to determine how far from the star the dust forms.