Like all true stars; massive stars are gravitationally confined thermonuclear reactors whose composition evolves as energy is lost to radiation and neutrinos. Unlike lower-mass stars ( M ≲8 M ⊙ ); however; no point is ever reached at which a massive star can be fully supported by electron degeneracy. Instead; the center evolves to ever higher temperatures; fusing ever heavier elements until a core of iron is produced. The collapse of this iron core to a neutron star releases an enormous amount of energy; a tiny fraction of which is sufficient to explode the star as a supernova. The authors examine our current understanding of the lives and deaths of massive stars; with special attention to the relevant nuclear and stellar physics. Emphasis is placed upon their post-helium-burning evolution. Current views regarding the supernova explosion mechanism are reviewed; and the hydrodynamics of supernova shock propagation and “fallback” is discussed. The calculated neutron star masses; supernova light curves; and spectra from these model stars are shown to be consistent with observations. During all phases; particular attention is paid to the nucleosynthesis of heavy elements. Such stars are capable of producing; with few exceptions; the isotopes between mass 16 and 88 as well as a large fraction of still heavier elements made by the r and p processes.
Search
Reviews
[Write a review of this article]
Find related articles from these CiteULike users
