Supernova 1993J as a spectroscopic link between type II and type Ib supernovae

SUPERNOVA 1993 J in the nearby galaxy M81 is one of the closest— and hence brightest—supernovae to be witnessed this century. The early spectrum of SN1993J showed1–3 the characteristic hydrogen signature of type II supernovae, but its subsequent evolution is atypical for this class of supernova. Here we present optical and infrared spectra of SN1993J up to… CONTINUE READING