A "supernova" is a nova (Latin "new") explosion of a very large star, creating a nebula of illuminated gas that is one of the most visible of all celestial phenomena.
Remember that a star is a nuclear fusion "engine" that is powered by the fusion of lighter elements to create heavier ones (up through iron). As lighter elements are fused to create heavier ones, energy is released in huge quantities. Gravity holds the star together against the outward force of all the fusion reactions, and the star operates in equilibrium. The extreme energy in the star allows for fusion reactions to continue to occur. But eventually the core of the star is largely sulfur and silicon. The contraction and heating of the star's core allows it to begin massively fusing silicon into iron, and this reaction absorbs energy rather than releasing it.
At some point, the energy created in fusion is insufficient to hold the star "up" against its own gravity, and, having exhausted its "regular" fuel, it will collapse. This is the supernova process. The star collapses causing the outer layers to violently explode outward as gases and dust. The compression of the body of the star in the collapse creates enormous thermal energy that supports the endothermic fusion reactions that create those trans-iron elements (up through uranium). It all occurs in a relatively short period of time. Afterwards, the remnant core may become a super-compressed neutron star, or even a black hole, if the star is massive enough.
Supernovae help enrich the interstellar medium with heavy elements, and shockwaves from the explosion may also trigger star formation. It is believed that the Sun and Solar System formed as a result of a nearby supernova.
While a supernova has not been observed from Earth since 1604, supernova remnants indicate that they occur, on average, about once every 50 years.
See the links and related questions below for more information
A supernova is an exploding star.
Well a supernova is the explosions or death of a star, so the Vela supernova is probably the supernova of the star vela!
That would be a supernova explosion.That would be a supernova explosion.That would be a supernova explosion.That would be a supernova explosion.
A supernova is the result of a collapsing star not a collapsing supernova.
No, a supernova is an explosion of a star. What left of a supernova are celestial bodies.
supernova supernova
The last supernova seen was in 1604. A Supernova has happened in over 400 Years!
A supernova is the destruction of a star - it does not have a weight.
A Supernova occurs when a star explodes. :)
It means that the star converts to a supernova. In other words, there is a supernova explosion.
The largest supernova is called a hypernova or type 1c Supernova. See related question.
A supernova is the explosion of a high mass star.