44 citations · 79 across the 2 of their papers we have counts for
4 papers
New results on the time variation of the radial abundance gradients from planetary nebulae
W. J. Maciel, L. G. Lago, R. D. D. Costa
New results on the time variation of the radial abundance gradients in the galactic disk are presented on the basis of four different samples of planetary nebulae. These comprise b…
An estimate of the time variation of the abundance gradient from planetary nebulae III. O, S, Ar, and Ne: A comparison of PN samples
W. J. Maciel, L. G. Lago, R. D. D. Costa
The time behaviour of the radial abundance gradients in the galactic disk is investigated on the basis of four different samples of planetary nebulae, comprising both smaller, homo…
Planetary Nebulae as a Chemical Evolution Tool: Abundance Gradients
W. J. Maciel, L. G. Lago, R. D. D. Costa
We have studied the time variation of the radial abundance gradients using samples of planetary nebulae, open clusters, cepheids and other young objects. Based on the analysis of O…
An estimate of the time variation of the abundance gradient from planetary nebulae II. Comparison with open clusters, cepheids and young objects
W. J. Maciel, L. G. Lago, R. D. D. Costa
The temporal behaviour of the radial abundance gradients has important consequences for models of the chemical evolution of the Galaxy. We present a comparison of the time variatio…