Transcript Document

1 Birth of a Star
Eagle Nebula
•Nebulae are large clouds of mainly
hydrogen gas and dust material.
Hydrogen is the most abundant
element in the universe and so this
gas forms the building block of each
star.
•Gravitational forces between
particles cause parts of the gas
cloud to become very dense.
2 Protostar
•As the gas cloud collapses the
hydrogen gas becomes even denser.
•The material pull itself into a disc
and starts rotating. GPE —› KE
•Particle make more frequent
collisions.
•The kinetic energy of the atoms gets converted to
heat energy causing the centre to heat up. KE —› Heat
•A hot ball of gas forms at the centre called a Protostar.
3 Nuclear Fusion Begins
• Eventually temperatures as
high as 15 million 0C are reached
at the centre of the ball of gas.
• These high temperatures allow
nuclear fusion reactions
between hydrogen nuclei.
•When fusion begins the star
gives out Electromagnetic
radiation.
•The solar wind pushes away
any material that has not
formed into a planet.
4 Stable period of a Star
Outwards
pressure
Inwards
Gravity
• Balanced forces act on the
star.
Balanced
Forces
Outward
EM Radiation
Pressure
• The star settles into a long
period of stability.
Outward
+
Gas
Pressure
Inwards
=
Pull of
Gravity
5 Summary of How a Star is Born