"When we recall the past, we usually find that it is the simplest things - not the great occasions - that in retrospect give off the greatest glow of happiness." -Bob Hope
When a very massive star reaches the end of its life, it runs out of burnable fuel. As a result, the core collapses, heats up and undergoes a runaway fusion reaction. While many heavy elements are formed and a tremendous amount of energy is released, the very core implodes, tearing apart the outer layers of the star in a supernova explosion.
Although the final catastrophe lasts only seconds, the explosion is visible for months, with the afterglow remaining detectable for thousands of years. What was the cause of this lasting electromagnetic radiation? In the aftermath of supernova 1987A, the closest supernova of the past 100+ years, we’ve learned the answer: radioactive elements created in the explosion itself.