Presupernova Evolution Research Articles

White dwarf models for type I supernovae and quiet supernovae, and presupernova evolution

Supernova mechanisms in accreting white dwarfs (WDs) are presented, i.e., the carbon deflagration as a plausible mechanism for producing Type I supernovae and electron captures to form quiet supernovae leaving neutron stars. These outcomes depend on accretion rate of helium, initial mass and composition of the WD. The various types of hydrogen shell-burning in the presupernova stage are also discussed.

Presupernova evolution of massive stars

view Abstract Citations (651) References (56) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Presupernova evolution of massive stars. Weaver, T. A. ; Zimmerman, G. B. ; Woosley, S. E. Abstract Results are reported for detailed calculations of the evolution of complete 15- and 25-solar-mass Population I stars from the ZAMS to iron core collapse. The structure of entire stars is computed using an implicit hydrodynamics computer code, and careful consideration is given to the complex nuclear processes that characterize the final evolutionary stages. The configurations of the stars at the begining of core collapse are presented, salient features of the presupernova models are examined, and implications for nucleosynthesis and the supernova explosions believed to follow are discussed. It is found that both stars form substantially neutronized 'iron' cores during hydrostatic silicon burning and that the element abundances in the larger star have ratios that are remarkably close to their solar system values over the mass range from oxygen to calcium, while the smaller star is characterized by large enhancements of Ne, Mg, and Si. Publication: The Astrophysical Journal Pub Date: November 1978 DOI: 10.1086/156569 Bibcode: 1978ApJ...225.1021W Keywords: Astronomical Models; Nuclear Fusion; Stellar Evolution; Stellar Mass; Stellar Structure; Supernovae; Abundance; Giant Stars; Gravitational Collapse; Hydrostatics; Silicon; Astrophysics; Collapse:Stellar Evolution; Evolution:Massive Stars; Nucleosynthesis:Stellar Evolution; Supernovae: Explosions full text sources ADS | Related Materials (1) Source Software: 2017ascl.soft02007W

The p-process in supernovae

The nucleosynthetic origin of the rare proton-rich isotopes, usually called ''p-process'' isotopes, is examined. A particularly interesting context for this synthesis is found to be explosive events characterized by peak temperatures in the range 2.0 to 3.0 x 10/sup 9/ K. At these temperatures a series of photodisintegration reactions operating upon a distribution of r- and s-process seeds produces an abundance pattern that displays striking similarities to that of the p-process nuclei in the solar system. The large proton densities usually required for such synthesis are not needed. Requisite conditions for this model are expected to occur naturally in those zones of supernovae that have experienced helium and perhaps carbon burning prior to explosion. Implications for supernova structure, presupernova evolution, and cosmochronology are discussed and a critical discussion of other current p-process models is presented.