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A Study of the Physical and Chemical Composition of Homogenous and Inhomogenous Models of the Sun


O'Reilly, James Donald (1950) A Study of the Physical and Chemical Composition of Homogenous and Inhomogenous Models of the Sun. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/13JF-3147.


In part I a radiative envelope, convective core model of the sun has been constructed on the assumption that the radiative opacity is due entirely to a Russell Mixture of heavy elements. The effect of scattering opacity is taken into account. Following the method of Schwarzschild and using the latest available data on the cross-section of the N[superscript 14] reaction, an estimate of the central temperature and composition of the sun has been made. It is found that the central temperature is approximately 17.5x10[superscript 6] °K, and that hydrogen, helium and heavy element abundances are .66, .31 and .03 respectively. A comparison is made with the results obtained from other recent investigations, and with the results of spectroscopic analysis of the solar atmosphere. In part II the requirements of stability, energy generation and age of the sun are used to construct models of the sun in which the mean molecular weight of the envelope differs from that of the core. The physical and chemical properties of three such models are listed. A comparison with the results of spectroscopic analysis is made, and the conclusion is drawn that the latter are more in accord with the assumption of chemical homogeneity in the sun. A note is appended upon the results of a recent similar investigation by Ledoux.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Physics and Mathematics) ; sun
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Minor Option:Mathematics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Christy, Robert F.
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1950
Record Number:CaltechETD:etd-10282008-150916
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4293
Deposited By: Imported from ETD-db
Deposited On:20 Nov 2008
Last Modified:31 Mar 2023 19:34

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PDF (O'Reilly_jd_1950.pdf) - Final Version
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