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 …

Nov 21, 2025 · 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 …

Sep 25, 2025 · 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 …

A supernova is far larger; a star in its supernova state may emit a billion times as much light as previously. After a few weeks it begins to dim, until it eventually ceases to exist; it's often …

Nov 12, 2020 · 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.

What is a supernova? Learn how massive stars explode, the types of supernovae, and the famous cosmic events captured by astronomers.

Mar 30, 2025 · A supernova is one of the most awe-inspiring and cataclysmic events in the universe, an explosion so powerful that it can outshine an entire galaxy for a short period.

Sep 15, 2025 · A supernova is a powerful and catastrophic event that occurs when a star explodes, releasing an immense amount of energy into space. This explosion can briefly …

Supernova definition: the explosion of a star, possibly caused by gravitational collapse, during which the star's luminosity increases by as much as 20 magnitudes and most of the star's …

Jun 19, 2023 · 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. …