Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-30T12:42:10.046Z Has data issue: false hasContentIssue false

Spectral Classification from a Theoretical Point of View

Published online by Cambridge University Press:  12 April 2016

Erika Bohm-Vitense*
Affiliation:
University of Washington

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We study the conditions under which a two-dimensional spectral classification according to Teff and ne is possible and when 3- or It-dimensional spectral classification is necessary because the classification criteria are unavoidably influenced by the metal and helium abundances. For late type stars, where molecular absorption becomes important for the continuum a seven-or more- dimensional classification may be necessary. At this point spectral classification may not be useful any more. We find generally that a derivation of the gravitational acceleration from the spectroscopically determined electron density is only possible if the helium abundance is known.

Type
VII Theoretically and Empirically Oriented Approach to Spectral Classification
Copyright
Copyright © Vatican Observatory 1979

References

Bohm-Vitense, E. (1975). In Problems in Stellar Atmospheres and Envelopes, G. Baschek, W.H. Kegel, and Traving, G., eds., Springer-Verlag: New York p. 21.CrossRefGoogle Scholar
Chalonge, D. and Divan, L. (1952). Ann. d’Astrophysique 15, 201.Google Scholar
Jamar, C., Macau-Hercot, D., Tompson, G.I., Houziaux, L. and Wilson, R. (1976). Ultraviolet Bright Star Spectro-photometrie Catalogue, European Space Agency.Google Scholar
Stromeren, B. (1963). In Basic Astronomical Data, Strand, K.Aa., ed., The University of Chicago Press: Chicago, p.123.Google Scholar
Unsold, A. (1948). Ann der Physik, 6, Folge 3, 124.Google Scholar