Download Life Cycle of the Stars

Life Cycle
of the
Stars
The Making of the Star
• Stars are formed in
nebulae, which are
large clouds of dust
and gas.
• Some of these clouds
can get be up to 1
light year long, from
base to tip.
• The majority of the
gas in these stellar
nurseries is hydrogen.
Gravity Pulls It Together
• Gravity at the center of
the cloud pulls the dust
together and starts to
form a clump of matter.
• As the ball of matter gets
bigger, the force of gravity
becomes stronger.
• As the clump of matter
grows, it begins to spin
and heat up.
A Star is Born
• When the core of the matter becomes hot
enough, thermonuclear fusion begins.
• This means that there is enough heat to
turn hydrogen to helium.
• Once this has happened a true star has
been born.
• The star shines with its own light.
• A solar wind then blows away the rest of
the dust and gas.
The Death of a Star
• How a star ends its life depends on its
mass or how much matter it was born with.
• Low and medium mass stars will end up
as white dwarfs.
• Stars that started with a lot of mass may
end their lives as black holes or neutron
stars.
The Dying Star
• When the star runs out of
helium to burn, the star starts
to collapse.
• The star begins to collapse
into itself. This collapse
causes the star to compact.
• After several more nuclear
processes the star burns all
the remaining helium and
loses its outer layers. Now,
the compacted core is
exposed to the universe.
The White Dwarf
• A White Dwarf is the
end of the life cycle
for Earth sized stars.
• They produce a
white-hot glow.
Neutron Stars
• When a star that is the size of 10 to 20
solar masses runs out of fuel to burn, it
explodes and the remaining matter
collapses to become a neutron star.
• This compact star is a few kilometers in
diameter and resembles a giant nucleus
made of neutrons.
Black Holes
• When a star of more than 30
solar masses runs out of fuel,
the collapse is so strong that
no known force can stop it or
resist it.
• This collapse happens at a
single point.
• The matter of the star, its
atoms and subatomic particles
are squeezed out of existence,
but the star remains its mass.
• Not even light can escape, that
is why it is called a black hole.