The effect of mass loss on the chemical yields from massive stars

Recent results on the calculation of the chemical yields from massive stars are rediscussed by taking into account the occurrence of mass loss by stellar wind during the core H(-) and He-burning phases. The new yields are found to be compatible with the observed distribution of chemical abundances in the solar system, except for He. The net enrichment of several elements over the Galaxy's lifetime is found to be consistent with the current estimate of the star formation rate, if a two phase process of galaxy formation (halo-disk) is adopted. The relative He to heavy element enrichment rate turns out to agree with the observational value when mass loss by stellar wind is taken into account.