Lots of people have heard of the word "supernova." It's gained a lot of popularity because of its incredible power. It's not surprising, after all, supernovae are the most powerful event in existence believe it or not. They're incredibly rare as well, only three have been observed in the Milky Way in the past thousand years, and that's a lot of space to blow up in.
You probably already know that a supernova is the death of a star. However, there are two ways this happens. In a binary star system, if a white dwarf begins to suck matter from its neighbor, then it will eventually gain too much mass to contain itself with gravity and will explode. The more commonly known tactic is when a massive star begins to run out of fuel for fusion. Its mass begins to fall into its core, which then collapses in upon itself and explodes. During these eruptions, supernovae can appear anywhere from a dim light in the sky, to a supposedly new star, to a bright light that outshines its entire galaxy to us.
Supernovae are incredibly important to the formation of the universe as well. All elements heavier than iron had to have been created in a supernova. Not only that, if you believe in the Big Band Theory, that itself was simply a massive supernova, if you'll pardon the repetition. They play a key role in sending various elements across the universe for solar system creation. Supernovae are even part of the reason we know the universe is expanding, and constantly provide evidence with which to study the Big Bang Theory.
I myself think supernovae are one of the coolest events in the known universe. My dream is to someday meet one, inevitably incinerating in the following explosion.