Evolution of the optical spectrum of SN 1987a in the Large Magellanic Cloud

Abstract

The evolution of the spectrum of SN 1987a is traced from 1987 February 26 to March 31. Based on the low-resolution spectroscopic data the authors identify the lines of H, He I, Na I, Fe II, Sc II, Ca II which are known to be present in Type II supernovae, and also present evidence for the existence of lines of Mg I, Ca I, O I, and N I. The authors discuss the evolution of the Hα profile, and draw attention to its complex structure around March 30.