A supernova (pl.: supernovae) is a powerful and luminous explosion of a star. A supernova occurs during the last evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion.
supernova, any of a class of violently exploding stars whose luminosity after eruption suddenly increases many millions of times its normal level. The term supernova is derived from nova (Latin: “new”), the name for another type of exploding star. Supernovae resemble novae in several respects.
A supernova of a star more than about 10 times the size of our sun may leave behind the densest objects in the universe— black holes. The Crab Nebula is the leftover, or remnant, of a massive star in our Milky Way that died 6,500 light-years away.
What Is a Supernova? | NASA Space Place – NASA Science for Kids
Supernovas 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...
A supernova is a star's colossal explosion at the end of its life, which can outshine its entire galaxy. Read about causes and types of supernovae here.
Supernova explosions are spectacular exceptions to that rule. Several different pathways can lead to a supernova explosion, one of which is the death of a supermassive star.
A supernova creates a huge amount of light for a short amount of time. Astronomers hoping to study such fleeting events look for points of light that suddenly appear in the night sky.