Clumping and large-scale anisotropy in supernova 1993J

Abstract

Profiles of emission lines in the spectra of supernova 1993J are shown. The differences between line profiles of forbidden and permitted transitions of the same species indicate not only that the ejecta are distributed in a non-spherically symmetric manner within the envelope, but also that the excitation conditions differ spatially. Such differential excitation conditions could result from an asymmetric distribution of the radioactive species powering the supernova light curve.