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He Abundance in Planetary Nebulae

Published online by Cambridge University Press:  25 May 2016

R. Gruenwald
Affiliation:
IAG-USP; Av. Miguel Stefano, 4200; 04301-904 São Paulo, SP, Brazil
S. M. Viegas
Affiliation:
IAG-USP; Av. Miguel Stefano, 4200; 04301-904 São Paulo, SP, Brazil

Abstract

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Type I planetary nebulae (PNe), defined as those with high He (and N) abundances, generally present bipolar geometries and high stellar temperatures. The main goal of this paper is to check if the empirically derived He overabundance for Type I PNs is real, or if it is a consequence of geometrical effects due to the bipolarity and/or to the ionization stratification due to the high stellar temperature of these objects.

Type
6. Stellar Knowledge to and from Light Elements
Copyright
Copyright © Astronomical Society of the Pacific 2000 

References

Corradi, R.L.M., & Schwarz, H.E. 1995, A&A, 293, 871 Google Scholar
Gruenwald, R., Viegas, S.M., & Broguiere, D. 1997, ApJ, 480, 283 Google Scholar
Harrington, J.P. et al. 1982, MNRAS, 199, 517 Google Scholar
Peimbert, 1978, in IAU Symp. 76, Planetary Nebulae, ed. Terzian, Y. (Dordrecht: Reidel), 215 Google Scholar
Peimbert, M. & Torres-Peimbert, S. 1983, in IAU Symp. 76, Planetary Nebulae, ed. Flower, D.R. (Dordrecht:Kluwer), 233 Google Scholar
Peimbert, M. & Torres-Peimbert, S. 1987, Rev. Mex. Astr. Astroph, 14, 540 Google Scholar
van den Hoek, L.B. & Groenewegen, M.A.T. 1997, A&AS, 123, 305 Google Scholar