Radiation pressure on grains as a mechanism for mass loss in red giants

A quantitative model is constructed for the process of radiation pressure on dust to explain the mass loss observed in cool giants. Results are given for six sample stars, demonstrating the effects of stellar luminosity, mass, and effective temperature on the mass loss rate. The envelope expansion velocity and average grain size related to the fraction of grain material condensed and the gas density is found to be the key factor in determining the feasibility of mass ejection under this mechanism. Subject headings: late-type stars - mass loss - radiative transfer