4 papers · 1 filter
Radial gradients and metallicities in the galactic disk
W. J. Maciel
Radial O/H abundance gradients derived from HII regions, hot stars and planetary nebulae are combined with [Fe/H] gradients from open cluster stars in order to derive an independen…
Stars and Planetary Nebulae in the Galactic Bulge
F. Cuisinier, J. Koppen, A. Acker +1
We compare the populations of Red Giant stars and Planetary Nebulae in the Galactic Bulge, in the light of recent determinations of their abundances patterns. We find both populati…
Some aspects of the chemical evolution of 4He in the Galaxy: the He/H abundance gradient and the Delta Y/Delta Z enrichment ratio
W. J. Maciel
Two aspects of the chemical evolution of 4He in the Galaxy are considered on the basis of a sample of disk planetary nebulae by the application of corrections due to the contaminat…
Chemical enrichment and star formation in the Milky Way disk; I. Sample description and chromospheric age-metallicity relation
H. J. Rocha-Pinto, W. J. Maciel, John Scalo +1
The age-metallicity relation of the solar neighbourhood is studied using a sample of 552 late-type dwarfs. This sample was built from the intersection of photometric catalogues wit…