| Abstract: | The evolution of the spectrum of SN1987a is traced from 1987 February 26 to March 31. Based on the low-resolution spectroscopic
data we 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, CaI, O I, and N I. We discuss the evolution of the Hα profile, and draw attention to its complex structure around March 30. Close
to the rest wavelength of Ha a double-peaked structure appeared in the profile with a peak-to-peak separation of ∼ 1400 km
s−1, suggestive of an expanding shell or disc of gas.
Using the available broadband photometric information, we also trace the evolution of the photosphere of SN1987a assuming
that it radiates like a supergiant. |
