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Main sequence models for massive zero-metal starsZero-age main-sequence models for stars of 20, 10, 5, and 2 solar masses with no heavy elements are constructed for three different possible primordial helium abundances: Y=0.00, Y=0.23, and Y=0.30. The latter two values of Y bracket the range of primordial helium abundances cited by Wagoner. With the exceptions of the two 20 solar mass models that contain helium, these models are found to be self-consistent in the sense that the formation of carbon through the triple-alpha process during premain sequence contraction is not sufficient to bring the CN cycle into competition with the proton-proton chain on the ZAMS. The zero-metal models of the present study have higher surface and central temperatures, higher central densities, smaller radii, and smaller convective cores than do the population I models with the same masses.
Document ID
19750033204
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Cary, N.
(Leander McCormick Observatory Charlottesville, Va., United States)
Date Acquired
August 8, 2013
Publication Date
November 1, 1974
Publication Information
Publication: Astrophysics and Space Science
Volume: 31
Subject Category
Astrophysics
Accession Number
75A17276
Distribution Limits
Public
Copyright
Other

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