What is a supernova?

A supernova is a powerful and luminous explosion that occurs at the end of a star’s life cycle. It marks one of the most energetic events in the universe and can briefly outshine an entire galaxy. Supernovae play a crucial role in dispersing heavy elements into space, which later become part of new stars, planets, and even life. During a supernova explosion, the core of a massive star collapses under gravity after it has exhausted its nuclear fuel. This core collapse causes the outer layers of the star to be violently ejected into space at incredible speeds. The sudden release of energy produces an extremely bright burst of light and radiation. In some cases, such as with white dwarf stars in binary systems, a supernova occurs when the star accumulates too much material from its companion, leading to a runaway nuclear reaction. The explosion creates shock waves that heat and enrich the surrounding interstellar medium with heavy elements like iron, gold, and uranium, which are essential for the formation of planets and life. After the explosion, what remains can be a neutron star, a black hole, or sometimes nothing visible at all, depending on the original star’s mass. Overall, supernovae are fundamental cosmic events that drive the evolution of galaxies and the chemical complexity of the universe.