What is a supernova? | Space

A supernova is what happens when a star has reached the end of its life and explodes in a brilliant burst of light. Supernovae can briefly outshine entire galaxies and radiate more energy than our sun will in its entire lifetime. They’re also the primary source of heavy elements in the universe. According to NASA, supernovae are “the largest explosion that takes place in space.”

Various civilizations recorded supernovae long before the telescope was invented in the 17th century. The oldest recorded supernova is RCW 86, which Chinese astronomers spotted in A.D. 185. Their records show that this “guest star” stayed in the sky for eight months, according to NASA.