Supernova 1987A 
On the night of February 23rd, 1987, telescope operator Oscar Duhalde stepped outside to admire the skies above the Andes Mountains of Chile. As he looked at a fuzzy patch of light known as the Large Magellanic Cloud — a small companion galaxy to the Milky Way — he saw a tiny star where none had been before. After talking to other astronomers, he realized that he was seeing something that no one had seen with their own eyes in almost four centuries: a supernova — the catastrophic death of a star.
The discovery ignited a scientific blitzkrieg, as astronomers turned the sights of every available telescope on and off Earth toward the supernova, which was designated Supernova 1987A.
They soon learned that the exploding star was a blue supergiant. That was a surprise, since theory said that only much larger red supergiants exploded as supernovae.
The star might actually have been a red supergiant, but it shrank and got hotter after it ate a companion star. This model says that as the companion fell inward, it stirred up the bigger star's innards, causing it to shrink and get hotter.
The supergiant burned through the fuel in its core, making heavier and heavier elements. Eventually, the core was converted to iron, which couldn't continue the process, so it collapsed. A shockwave rebounded from the collapse, blasting the star's outer layers to bits and creating a sight not seen in Earth's skies in four centuries: a supernova.
Script by Damond Benningfield, Copyright 2011