NEUTRINO PROCESSES AND PAIR FORMATION IN MASSIVE STARS AND SUPERNOVAE,
CALIFORNIA INST OF TECH PASADENA
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The paper traces the physical properties of matter inside highly evolved stars, on the assumption that the whole material of the star is non-degenerate and that the star is in quasi-hydrostatic equilibrium. When these conditions are satisfied, the physical evolution of a particular element of material is insensitive to the stallar model but not to the total mass of the star. Our considerations refer explicity to stars of mass greater than approx. 10 micro sun but less than 1,000,000 micro sun, at which point general relativistic considerations become paramount. In Parts I and II neutrino-loss processes and neutrino-loss rates are examined. In Part III a method is developed for calculating the product mu beta as a function of temperature when electron positron pair formation is taken into account. In this product mu is the mean molecular weight and beta the ratio of gas pressure to gas plus radiation pressure. In Part IV the internal energy of matter is considered again as a function of temperature, and including the effects of pair formation. Parts V, VI, and VII are concerned with nuclear reactions, in particular with oxygen burning, the alpha-process, and the e-process. In the final Parts VIII and IX the onset of a supernova of Type II is considered in which the central core implodes while the mantle and envelope of the star explode. These considerations are tentative because the discussion now involves the structure of the whole star, and hence of the stellar model. It is emphasized that massive stard do not necessarily become Type II supernovae but can collapse to general relativistic singularities.