2. What is a star?
A star is a giant
luminous ball of super
heated gas. Just like
our star, The Sun.
They are scattered
throughout the space
so far away, that we
would need one
hundred thousand
years to reach them.
3. How are stars born?
They begin in clouds of
dust and gas very far
away.
Gravity gathers
hydrogen gas and
particles of dust and the
clouds grow more dense.
As it squeezes itself
tighter, the hydrogen
heats up to a fantastic 18
million ºF (10 million
ºC). Nuclear fusion turns
hydrogen into helium
and the fire ignites.
4. Where are stars born?
Stars are born in vast clouds
in the space called nebulae.
A nebulae is an interstellar
cloud of dust, hydrogen,
helium and other ionized
gases.
These clouds are also called
molecular clouds. Here,
temperatures can drop
down until -441 ºF (-263 ºC).
5. What color are stars?
The color of stars depend on
how hot they are. The
temperature varies along a
band on a graph called the
Main Sequence.
The colors go from hot and
bright blue-white to cool
and dim red.
6. What is the biggest star?
The biggest stars are
the supergiants.
Antares is 700 times as
big as the Sun. The
largest star we know
of, is called VY Canis
Majoris.
We could probably fit
the Sun inside VY
Canis Majoris 2100
times.
7. How many stars are
there?
What makes stars twinkle?
Stars twinkle because the Earth’s
atmosphere is never still. Starlight
twinkles as the air wavers.
It is hard to know how many stars
there are in the universe. But
astronomers guess there are about
200 billion billion.
What makes stars glow?
They glow because the enormous pressure
deep inside generates nuclear fusion
reactions.
