W. J. Maciel - Abstract #66ABUNDANCE GRADIENTS IN THE GALAXYW. J. Maciel Stellar Abundances, ed. B. Barbuy, W. J. Maciel, J. C. Gregório-Hetem, IAG/USP, São Paulo, 79-90 (1996) The abundance gradients observed in the Galaxy and other spiral galaxies are reviewed, especially regarding radial gradients. A summary is given of the main observational evidences based on HII regions, planetary nebulae (PN), stars, and supernova remnants (SNR), emphasizing the PN results. Finally, a discussion is given of the physical processes causing the gradients, and of their time evolution. |