supernova

supernova
[ˌs(j)uːpəˈnəʊvə]
(pl. supernovae -viː 或 supernovas)

(Astronomy)a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass
(天文)超新星
Supernovae are believed to be supergiant stars which have exhausted the hydrogen and helium fuel in their interiors. Gravitational contraction then leads to runaway thermonuclear reactions involving heavier elements, catastrophically disrupting the star and ejecting debris at speeds of up to a tenth of the speed of light and temperatures of hundreds of thousands of degrees. Within the resulting shell of material may be left a pulsar or a black hole. Though frequently observed in other galaxies, only three supernovae have been recorded in our own Galaxy

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