Type Ib-Ic-IIb-IIL Supernovae: Common Envelope Evolution, Instabilities, and Circumstellar Interaction

Abstract

The origin of an observational diversity of supernova types, namely, Type Ia, Ib, Ic, II-P, II-L, IIb, and IIn, has not been well understood. We propose a new scenario that explains how such a diversity can result from the common envelope evolution of binary stars. The recent nearby supernovae SN 1993J and SN 1994I have provided particularly useful material to clarify the supernova-progenitor connection. For a progenitor of Type IIb supernova 1993J, we propose that merging of two stars in a close binary is responsible for the formation of a thin H-rich envelope. For a progenitor of Type Ic supernova 1994I, we propose a bare C+O star that has lost both H and He envelope after common envelope phase. By generalizing these scenarios, we show that common envelope evolution in massive close binary stars leads to various degree of stripping of the envelope mass of massive star. This can naturally lead to the explanation of the origin of Type II-L, IIn, IIb, Ib, and Ic in a unified manner. The binary hypothesis to explain the diversity of supernovae can be substantiated with new information on SN IIb 1993J and SN Ic 1994I. Hydrodynamical and nucleosynthesis models for these supernovae (including Rayleigh-Taylor instabilities) and their light curves are compared with observations. Based on these modeling, we suggest that the subluminous SN I 1993R might be a SN Ib originating from the smallest mass progenitor. Finally, circumstellar interactions of SN 1993J are examined to compare with X-ray observations and infer the density structure and instabilities of the ejecta.