A polytropic model for the helium shell flash

A model consisting of two polytropes is constructed, to represent a helium core of a star during the helium shell flash occurring at the onset of helium burning in a degenerate core. The maximum temperature reached during the flash can be predicted as a function of core mass and mass inside the helium burning shell. This temperature will generally be too low for the production of neutrons out of¹⁴N. Some additional results on the helium shell flash in a star of 1.3M are also presented.Supported in part by the National Science Foundation GP-9433] and the Office of Naval Research Nonr-220(47)].On leave of absence from the Max Planck Institut für Physik und Astrophysik, München.