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A Comparison of Nebular Distance Scales

Published online by Cambridge University Press:  07 August 2017

M. Samland
Affiliation:
Institut für Theoretische Physik und Sternwarte, D-2300 Kiel, Germany
J. Köppen
Affiliation:
Institut für Theoretische Physik und Sternwarte, D-2300 Kiel, Germany
A. Acker
Affiliation:
Observatoire de Strasbourg, 11, rue de l'Université, 67000 Strasbourg, France
B. Stenholm
Affiliation:
Lund Observatory, Box 43, S-221 00 Lund, Sweden

Extract

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Determination of the positions of central stars of planetary nebulae in the HR-diagram requires the knowledge of nebular distances. For almost all nebulae, these can only be given in terms of statistical scales. These scales have in common that they assume all nebulae to have the same structure (e.g. constant density) and that a unique ionized mass-radius relation exists. If the mass-radius relation is given by Mion = M 0 · (R/R 0)η, the distance d(pc) of planetary nebulae can be expressed as a function the de-reddened Hβ-flux (erg cm−2s−1) and the angular radius θ(arcsec): M0 and R0 are in solar masses and pc (Te = 10000 K, He/H = 0.1). The parameter η characterizes the distance scale: e.g. Shklovsky (1956) η = 0, Maciel L. Pottasch (1980) η = 1, Pottasch (1984) η = 3/2, Daub (1982) η = 5/3, and Kwok (1985) η = 9/4.

Type
III. Highlights on the Nebulae
Copyright
Copyright © Kluwer 1993 

References

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