(Image Link (to zoom))
My sister-in-law asked me this excellent question the other night. I completely forgot about SN 1987A.
SN 1987A was a supernova in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud, a nearby dwarf galaxy. It occurred approximately 51.4 kiloparsecs from Earth, approximately 168,000 light-years, close enough that it was visible to the naked eye. It could be seen from the Southern Hemisphere. It was the closest observed supernova since SN 1604, which occurred in the Milky Way itself. The light from the new supernova reached Earth on February 23, 1987.
Of course I didn't see this one because it was only visible in the Southern Hemisphere but I followed it pretty closely. As noted above, it was the first close supernova since A.D. 1604.
From the light curve you can see it took several months for the phenomenon to brighten and dim.