7th Sep '25

Life Cycle of Stars

Individual stars, including the Sun, do not stay the same forever. Stars form when enough dust and gas from space is pulled together by gravitational attraction. Smaller masses may also form and be attracted by a larger mass to become planets.

Fusion processes in stars produce all naturally occurring elements. These elements may be distributed throughout the Universe by the explosion of a star (supernova) at the end of its life. We know our Sun is not a first genteration star because it contains trace elements for example Magnesium and Oxygen, while the early Univers only contained Hydrogen.

Great clouds of gas and dust are called
The dust and gas comes together under its own gravity, causing it to heat up. It becomes so hot that Nuclear Fusion begins and the star is known as a .
The star continues to contract until the outward 'radiation pressure' balances the inward gravitational attraction. The star is now stable and in its . This is where the Sun currently is.
Once the Hydrogen runs out in the star it expands, and its surface cools to form a .
This slowly shrinks to form a dwarf...
...which cools to a dwarf...
...a dwarf,...
...and eventually a dwarf which is too cool to give out light.
The star collapses in on itself and explodes as a throwing dust into space
The matter left behind forms an incredibly dense neutron star.

If it is massive enough then not even light can escape its gravity and becomes known as a