On Nov. 6, 1572, the German astronomer Wolfgang Schulër observed a supernova with his bare eyes.
He spotted the exploding star in the constellation Cassiopeia. It was as bright as Venus and could even be seen during the day. Astronomers were really confused, because it looked like a star just appeared out of nowhere. Schulër may have been the first to see it, but the Danish astronomer Tycho Brahe is widely credited for the discovery. Brahe studied it in detail and wrote a whole book about this so-called "new star." It then became known as "Tycho's Star."
At the time, supernovas had not yet been discovered. Tycho's Star was finally classified as a supernova in the 1940s. Scientists now think it was a small star called a white dwarf that exploded thousands of years ago. Because Tycho's Star is 13,000 light-years from Earth, it took a while before anyone could see it.
