W. J. Maciel -
Abstract #137
RADIAL ABUNDANCE GRADIENTS FROM PLANETARY NEBULAE AND YOUNG OBJECTS: AGE EFFECTS
W. J. Maciel, T. S. Rodrigues, R. D. D. Costa
IAU Symposium No. 283, Ed. A. Manchado, L. Stanghellini, D. Schönberner,
424-425 (2012)
We discuss the effects on the time variation of the gradients resulting from our
determinations of the age distributions of CSPN. The main conclusions are: (i) for most CSPN
with accurate radial velocities the kinematic ages are usually under 3 Gyr, so that the differences
between the gradients of these objects and of younger objects are expected to be small; (ii) results
based on age-metallicity relations suggest that there is an older PN population for which the
gradients are steeper, in agreement with open cluster data.
