W. J. Maciel -
Abstract #97
CHEMICAL ABUNDANCES OF PLANETARY NEBULAE TOWARDS THE GALACTIC ANTICENTER
R. D. D. Costa, M. M. M. Uchida, W.J. Maciel
Astronomy and Astrophysics 423, 199-207 (2004) In this paper we report new observations and derive chemical abundances for a sample of 26 planetary nebulae (PN) located in the anticenter direction. Most of these nebulae are far away objects, located at galactocentric distances greater than about 8 kpc, so that they are particularly useful for the determination of the radial gradients at large distances from the galactic center. A comparison of the present results with previously determined abundances suggests that the radial abundance gradients flatten out at distances larger than about 10 kpc from the center.
