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Theoretical studies of massive stars. I - Evolution of a 15-solar-mass star from the zero-age main sequence to neon ignitionThe evolution of a star with mass 15 times that of the sun from the zero-age main sequence to neon ignition has been computed by the Henyey method. The hydrogen-rich envelope and all shell sources were explicitly included in the models. An algorithm has been developed for approximating the results of carbon burning, including the branching ratio for the C-12 + C-12 reaction and taking some secondary reactions into account. Penetration of the convective envelope into the core is found to be unimportant during the stages covered by the models. Energy transfer from the carbon-burning shell to the core by degenerate electron conduction becomes important after the core carbon-burning stage. Neon ignition will occur in a semidegenerate core and will lead to a mild 'flash.' Detailed numerical results are given in an appendix. Continuation of the calculations into later stages and variations with the total mass of the star will be discussed in later papers.
Document ID
19750045667
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Endal, A. S.
(Florida, University, Gainesville, Fla.; NASA, Goddard Space Flight Center Greenbelt, Md., United States)
Date Acquired
August 8, 2013
Publication Date
April 15, 1975
Publication Information
Publication: Astrophysical Journal
Volume: 197
Subject Category
Astrophysics
Accession Number
75A29739
Distribution Limits
Public
Copyright
Other

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