supernova
noun
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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, 19 Dec. 2025
In the first scenario, a quickly spinning star goes supernova before fissioning into two, sub-solar neutron stars.
—Andrew Paul, Popular Science, 17 Dec. 2025
Follow-up observations showed the light behaved like a kilonova, a fast-fading and red, before unexpectedly brightening, turning blue, and revealing hydrogen, classic signs of a supernova.
—Neetika Walter, Interesting Engineering, 16 Dec. 2025
The ancient blast occurred when the cosmos was just 5 percent of its current age, and the supernova’s light has been traveling through space ever since.
—Clara Moskowitz, Scientific American, 9 Dec. 2025
See All Example Sentences for supernova
Cite this Entry
“Supernova.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/supernova. Accessed 1 Jan. 2026.
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supernova
noun
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