ON THE GENERATION OF MASS-LOSS IN COOL GIANT STARS DUE TO PROPAGATING SHOCK-WAVES

In the present work, I investigate mass loss in late-type giant stars produced by propagating shock waves, assuming both monochromatic waves and acoustic frequency spectra. In my monochromatic wave computations, the wave period is varied by a factor of 50. My wave models show that short-period waves produced in stellar convective zones do not play any direct role in generating the observed mass loss, except for episodic mass-loss events. However, these waves are important for heating stellar chromospheres. Continuous mass-loss solutions are obtained when the wavelengths are comparable to or larger than a stellar radius. In the case of Arcturus, a mass-loss rate between 10-10 and 10-11 M⊙ yr-1 is found, and the final flow speed of the wind is larger than 40 km s-1, which are close to the observed values. I demonstrate the presence of mass loss by applying three mass-loss criteria, which involve the actual and the time-averaged flow and sound speeds.