On presupernova dynamical mass ejection by non-detonated stellar cores

Stars in the range of 4 to 8 solar masses are known to develop degenerate carbon-oxygen cores of about 1.4 solar masses. Arguments are presented why, contrary to past assumption, carbon ignition may not lead to the formation of a detonation wave. Rather, an initially subsonic burning front results which subsequently may be brought under control by adiabatic expansion. This dynamic phase leads to a centrally incinerated and expanded core. The loosely bound red-giant envelope is ejected to form an extended nebula. Neutrino cooling of the core finally induces collapse. Provided that sufficient energy is liberated in the dynamic formation of a neutron star, a supernova event will result. The distended nebula is ideally suited for the production of the visible supernova light curves. Thus, carbon nondetonation may give a viable alternative evolution to supernovae that avoids the impasse encountered by the detonation-disrupted models.