Optical Spectra of the Supernova 1993J in M81

Abstract

We present the optical spectra of supernova 1993J which occurred in M81. The observations were made on 1993 March 31, covering the wavelength region between 4500 and 9000 Å. Although there are no remarkable emission features, weak emission lines at both λ5858 and 6559 Å exist in the spectra. These emission lines can probably be attributed to He I λ5876 Å and Hα A6563 Å, respectively. The He I emission is blueshifted by 800 km s–1 with respect to the H I velocity of the position of SN 1993J.