W. J. Maciel -
Abstract #68
CHEMICAL ABUNDANCES FOR A PLANETARY NEBULAE SAMPLE LOCATED OUTSIDE THE SOLAR CIRCLE
R. D. D. Costa, C. Chiappini, W. J. Maciel, J. A. Freitas Pacheco
Advances in stellar evolution, ed. R. Rood, A. Renzini, Cambridge University Press, Cambridge 159-162 (1997) The Galactic disk shows a radial gradient of chemical abundances, with larger values in the inner region and a decreasing towards the edge. In order to check the behavior of this gradient at galactocentric distances larger than that of the Sun, we derived chemical abundances for a sample of planetary nebulae located outside the solar circle. Our results show a decreasing of the galactocentric gradient for distances larger than 9 kpc, and different behaviors for type-I and type-II nebulae.
