supernova
noun
Did you know?
A nova, despite its name, isn't actually a "new" star, but rather one that wasn't noticed until it exploded, when it may increase in brightness by a million times before returning to its previous state a few days later. 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 replaced by a black hole. (Though remains that were shot out into space may survive; those of a great supernova seen in A.D. 1054 are now known as the Crab Nebula.) All this may serve as a warning to those human stars whose fame explodes too rapidly; supernovas of this kind have sometimes vanished by the following year.
Examples of supernova in a Sentence
Robert Lea, Space.com, 12 Mar. 2026
In the early 2000s, scientists first saw these conspicuous cataclysms, which can shine much longer and be more than 10 times brighter than a normal supernova.
—Joseph Howlett, Scientific American, 11 Mar. 2026
Located one billion light-years from Earth, SN 2024afav was a prime example of a superluminous supernova—an event that’s at least 10 times brighter than a large star’s explosion.
—Andrew Paul, Popular Science, 11 Mar. 2026
Any nearby supernova would likely also have injected lots of the radioactive isotope iron-60.
—James Dinneen, Quanta Magazine, 2 Mar. 2026
See All Example Sentences for supernova
Cite this Entry
“Supernova.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/supernova. Accessed 21 Mar. 2026.
Copy CitationKids Definition
supernova
noun
