Evolution of massive stars. II. The influence of initial composition and mass loss

Journal Article · Thu Jul 01 04:00:00 EDT 1982 · Astrophys. J., Suppl. Ser.; (United States)

DOI:https://doi.org/10.1086/190806· OSTI ID:5130451

Brunish, W M; Truran, J W

We have studied the evolution of 15, 30, and 40 M/sub sun/ stars with compositions Y = 0.28 and Z = 0.01, 0.001, and 0.0002, and of 50 M/sub sun/ stars with Y = 0.28, Z = 0.0002. These models have been evolved from the zero-age main sequence through core helium burning and up to the point of carbon ignition. All models were evolved with and without the inclusion of mass loss. We have used a moderate mass loss rate with different efficiency factors for main-sequence and blue supergiant stars. Our results indicate that all massive stars ignite helium as blue supergiants. Stars with initial masses M/sub i/< or approx. =30 M/sub sun/ evolve redward very slowly and spend less than 1% of their total lifetimes as red supergiants. Above 30 M/sub sun/, the rate of redward evolution increases dramatically. The effect of a reduction in the initial metal content relative to solar abundances is to cause the models to be bluer and, in general, slightly more luminous at comparable stages of evolution. In the absence of mass loss, models with M/sub i/< or =30 M/sub sun/ and Z< or =0.001 do not become red supergiants prior to carbon ignition. Mass loss causes all models to evolve redward more rapidly during core helium burning.

• Research Organization: Department of Astronomy, University of Illinois at Urbana-Champaign
• OSTI ID: 5130451
• Journal Information: Astrophys. J., Suppl. Ser.; (United States), Journal Name: Astrophys. J., Suppl. Ser.; (United States) Vol. 49:3; ISSN APJSA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics &amp; Cosmology-- Stars &amp; Quasi-Stellar
Radio &amp; X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON BURNING
CNO CYCLE
HELIUM BURNING
MATHEMATICAL MODELS
STAR BURNING
STAR EVOLUTION
STAR MODELS