Abstract:
Spectroscopic observations of SN 1987a obtained during 1987 August 30 – September 8 from Vainu Bappu Observatory, Kavalur, are presented; the spectrum is compared and contrasted with the spectra recorded at earlier epochs. The lines of Fe II are weakening, whereas the forbidden lines are strengthening. The presence of [Ca II] and the emergence of [0 I] suggests that the electron density in the envelope was about 10/sup9/cm/sup3 at the end of May, and reduced to a value below 10/sup 8/cm/sup 3 by the end of August.