Supernovae

A rendition as to what a star going supernova may look like

A supernova forms when the core of a star begins to cool, causing it to exert less outward pressure on the star, causing it to collapse in on itself due to the enormous force of gravity. This rapid collapse causes the outer surface of the star to explode, creating shockwaves and spewing large amounts of radiation and light energy that traverses the universe, into our telescopes and radiation instruments.

To better understand what supernovae are, it is important to grasp the physics behind it all (get it?). First, let us discuss the anatomy of stars. Stars like our sun generally consist of a plasma held together by the forces of gravity and pressure. If not for gravity, stars would never form and would just float around without being attracted to anything. Gravity truly is the defining force of the universe. 

Anyway, when a star begins to die and the production of energy begins to dwindle, the pressure that keeps the star from collapsing in on itself from the center of the star gradually decreases, eventually causing the gravity exerted on it to overcome the outwards pressure. When a star is in equilibrium (i.e the outwards force exerted from the star is equal to the inwards force of gravity) it exists normally, but when it approaches the end of its life span, the nuclear power at its core reduces, and so the outwards force becomes lesser than the inwards force. Thus, the star collapses on itself and explodes in a fiery spectacle visible from millions of light-years away.

After this explosion, the dense core of the star remains, with a cloud of extremely hot gas expanding around it. This gas is called a nebula, and we can see it even from our naked eye. As discussed in a previous post, if a star over 10 times the mass of our sun explodes in a supernova, the end result may not be a nebula, but rather a black hole. Interesting, right?

What do you think of Supernovae? Let me know in the comments!