Supercritical winds from cool 'canonical' stars caused by evolution on the main sequence

Abstract

Even the very slow expansion of a star's radius due to evolution on the Main Sequence is shown to be supercritical for cool stars without coronae. Since steady sphericaily-symmetric supercitical solutions are theoretically impossible, unsteady supercritical solutions are studied. It is seen that smooth sonic transitions are possible in the unsteady case, but are accompanied by enhancement of pressure over the critical values.