STELLAR MASS-LOSS - A CENTRAL PROBLEM IN ASTROPHYSICS

Mass loss is of central importance for the theory of stellar evolution which in turn, has as one of its most important applications the unde rstanding of the metallicity evolution in galaxies and in the universe . It is emphasized that mass loss is not yet sufficiently well underst ood that a save extrapolation to the low metallicity case, i.e. the ea rly universe, can be made. Especially, the dependence on the stellar p arameters of the mass loss in the Wolf-Rayet phase, which is important for the enrichment of light elements such as C and N, is extremely un certain.