Dictionary of Space Concepts

Source: Midjourney (2023, May 25). AI illustration of a supernova. Midjourney. midjourney

Definition:

Brief, bright illumination of a supermassive star at the end of its lifetime by an explosion in which the original star itself is destroyed.

As it dies, a supermassive star goes through various stages of fusing different elements, forming a red supergiant. During this process, more and more heavy material is deposited onto the stellar core. Once the core’s mass tips past a certain threshold it collapses under its own gravity (meaning it cannot withstand its own gravitational force). The outer layers are blasted outwards in a supernova, the biggest explosion known to occur in the Universe. 

At its peak, a supernova can be brighter than an entire galaxy. Supernovae reach their peak luminosity in a matter of days, so their appearance and early decline can be observed in real time.

Etymology:

from Latin super “beyond”, “over and above” and stella nova “new star”

Translations: