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Hydrogen Deficient Planetary Nebulae: Preliminary Results

Published online by Cambridge University Press:  12 April 2016

S.R. Pottasch ,
A. Mampaso ,
A. Manchado  and
J. Menzies
S.R. Pottasch
Affiliation:
University of Groningen
A. Mampaso
Affiliation:
Instituto de Astrofisica de Canarias
A. Manchado
Affiliation:
Instituto de Astrofisica de Canarias
J. Menzies
Affiliation:
South African Astronomical Observatory

Abstract

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New spectra of A78 and A58 at different positions in the nebulae are presented. An abundance gradient is found in A78, extending quite close to the center. Similarly the nebulous knot near the center of A58 has considerably higher heavy element abundances than the outer regions of this nebula. The ionization state is considerably lower in A58 than A78. In A78 most of the neon is in the form of Ne+3 and Ne+4, indicating that the standard ionization correction factor as used by Jacoby and Ford, is substantially in error. Finally, the very high infrared excesses found in this nebulae are discussed.

Information

Type
VII Related Objects
Information
International Astronomical Union Colloquium , Volume 87: HydrogenDeficient Stars and Related Objects , 1985 , pp. 359 - 365
Copyright
Copyright © Reidel 1986

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