On February 24, 1987 at LCO, Ian Shelton and Oscar Duhalde became the first official observers of Supernova 1987A (SN 1987A).
SN 1993J was at a very similar distance, in M82's larger companion galaxy M81, and SN 1987A was much closer.
Although small by modern standards, the Southern Observatory nevertheless became famous for its role in the discovery of SN 1987A when UofT astronomer Ian Shelton spotted the supernova while attempting to fix another disused telescope at the site.