Download Stars - BrainBytes

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Stars are born from great clouds of gas and
dust
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They mature, grow old, and die
The more massive a star is, the shorter its life
A star is a sphere of super-hot gases – mostly
hydrogen and helium
Vary greatly in their masses, size and density
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The range of colors a star emits depends on its
surface temperature.
Cool stars  redder in color
 Stars 3900-7000 degrees C  yellow
 Stars 7000-9500 degree C  white
 Stars 9500+ degrees C  blue
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Diagram that pictures the life of a star
Classifies stars based on temperature and
luminosity
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Majority of stars (about
90%) fall in this category
Runs from upper left
(high luminosity, high
surface temperature ) to
lower right (low
luminosity, low surface
temperature)
Life span: 1 million – 1
billion yrs
Actively fuse hydrogen
and helium
Example: our Sun
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Closest star to Earth
Middle aged star  predicted to keep shining
for 5 billion more years
Diameter: 870,000 miles wide
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If the sun were hollowed, you could fit 330,000
Earths inside
Core Temperature: 27 million degrees
Fahrenheit
Made out of mostly hydrogen
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Most stars are red dwarfs
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Stars with less than 50% the mass of the sun
1/10,000th the energy of the sun
It is estimated there are between 200-400 billion
stars in our galaxy
The closest star to Earth, besides the sun is
Proxima Centauri – located 4.2 light years
away
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On the fastest spacecraft, it would still take 70,000
yrs to get there
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Greater luminosity
than main sequence
stars
Star is moving toward
end of life
Helium sinks to the
center of the core
Raises star’s temp.
 Outer shell begins to
swell
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Beginning of star
shedding its outer
layer
Becomes a small,
dense body
Cools for billions of
years and eventually
becomes dark and
produces no energy
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A few stars do not
follow the
evolutionary path and
go out with a bang
Violent explosion that
leaves behind a small
core known as a
neutron star
If the remnant is large
enough = black hole