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A quantitative analysis of the atmospheres of three peculiar low-luminosity B stars

Citation

Stewart, John C. (1955) A quantitative analysis of the atmospheres of three peculiar low-luminosity B stars. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-02022004-095522

Abstract

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High-dispersion spectra of HD 37058, HD 37129 and HD 135485, three B stars exhibiting spectral peculiarities, have been studied on the basis of model atmospheres, with a view to detecting abundance anomalies. An approximate theory of high-temperature model atmospheres, applicable to stars in the range of spectral type B 1 - B7 and luminosity classes IV and V, has been developed and applied to the prediction of Balmer line profiles and total intensities of other lines. Temperatures, surface gravities and helium abundances of the three peculiar stars and two standard B stars, [...] Peg and [...] Scl, have been determined. The abundances of other elements have been found from curves of growth using theoretical line strengths. The values of surface gravity derived imply luminosities lower than those of the standard stars. The helium abundance derived for HD 135485 is remarkably large; a sizable titanium excess and an oxygen deficiency were detected in HD 37058.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Astronomy
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Münch, Guido
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1955
Record Number:CaltechETD:etd-02022004-095522
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-02022004-095522
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:451
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:04 Feb 2004
Last Modified:26 Dec 2012 02:29

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