An important area of current astronomical research concerns the study of mass loss of red giant stars as they evolve to white dwarfs through the "planetary nebula" stage. It is now believed that this loss occurs as a wind of atomic particles. The intensity of this wind increases over the course of several thousand years until the envelope of the star is peeled off in a very fast wind at a rapid rate. The Principal Investigator (PI) proposes to continue previous studies of this phenomenon by using a determining the amount of mass lost in this wind in a large sample of red giants from the strength of two carbon monoxide emission lines in the nebular material surrounding them. The amounts of mass loss will be correlated against known stellar parameters such as stellar mass, luminosity, radius, and chemical composition to permit an empirical model to be developed as to how mass is lost during this critical brief stage of evolution.