Supernova, nuclear synthesis, fluid instabilities, and interfacial mixing.

Supernovae and their remnants are a central problem in astrophysics due to their role in the stellar evolution and nuclear synthesis. A supernova's explosion is driven by a blast wave causing the development of Rayleigh-Taylor and Richtmyer-Meshkov instabilities and leading to intensive interfacial mixing of materials of a progenitor star. Rayleigh-Taylor and Richtmyer-Meshkov mixing breaks spherical symmetry of a star and provides conditions for synthesis of heavy mass elements in addition to light mass elements synthesized in the star before its explosion.

Explosive nucleosynthesis in stars.

Recent calculations provide convincing evidence that the naturally occurring nuclei were produced in explosions. The required temperature, density and expansion rate strongly suggest that before the explosion the objects were ordinary evolved massive stars. We review these new developments and present a new table indicating our hypothesis concerning the origin of the nuclei in the mass range 20 < or = A < or = 62.