Stars go through many traumatic stages in their lives
Stars initially form from a cloud of dust and gas called a nebula.
The force of gravity pulls the dust and gas together to form a protostar.
The temperature rises as the star gets denser and more particles collide with each other.
When the temperature gets high enough, hydrogen nuclei undergo nuclear fusion to form helium nuclei.
This gives out huge amounts of energy, which keeps the core of the star hot.
A star is born.
The star enters a long stable period where the outward pressure caused by the nuclear fusion that tries to expand the star balances the force of gravity pulling everything inwards.
In this stable period, it’s called a main sequence star and it typically lasts several billion years. (The sun is in the middle of this period.)
Eventually the hydrogen begins to run out. The star then swells into a red giant (if it is a small star) or a red super giant (if it is a larger star). It becomes red because the surface cools.
Fusion of helium (and other elements) occurs. Heavier elements (up to iron) are created in the core of the star.
A small-to-medium-sized star like the sun then becomes unstable and ejects its outer layer of dust and gas. This leaves behind a hot, dense solid core-a white dwarf.
As a white dwarf cools down, it emits less and less energy. When it no longer emits a significant amount, it is called a black dwarf.
Big stars start to glow brightly again as they undergo more fusion and expand and contract several times, forming elements as heavy as iron in various nuclear reactions.
Eventually they’ll explode in a supernova, forming elements heavier than iron and ejecting them into the universe to form new planets and stars. Stars and their life cycles produce and distribute all naturally occurring elemen
The exploding supernova throws the outer layers of dust and gas into space, leaving a very dense core called a neutron star. If the star is massive enough, it will become a black hole-a super dense point on space that not even light can escape from \n .