STARS and

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STARS and GALAXIES
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A STAR PARTY!!!The largest gatherings in the
universe!

• Galaxies-Are large scale groups of stars that are
  bounded together by gravity.
• Roughly 100 billion stars are contained within a
  galaxy.

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WHAT ELSE IS IN A GALAXY?

• Galaxies also contain gases and dust.
• There are two bright nebulas.
• One glows bright from the hot gases within.
• Others shine by reflecting light from nearby
  stars.

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JUST HOW MANY GALAXIES ARE THERE?Space is that
big!!!

• Estimated 50 billion to 1 trillion galaxies in
  the known universe.
• the closest to Earth is The Milky Way.

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THE MILKY WAYOur home in the stars

• Our galaxy is a spiral galaxy, in which the sun
  is one in a billion stars that are found inside.
• All the stars in the Milky Way have their own
  motion, some are moving towards the sun while
  others are moving away from our sun.
• Our sun is located on one of the spiral arms. It
  is rotating around the nucleus at 250 km/s.

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THE MILKY WAYOur home in the stars

• You can look outside on a clear dark night and
  see the Milky Way!!!
• In the night sky it will appear as a band of
  stars that stretches across the sky.
• It will appear milky in the sky.
• You are actually looking at one of the arms of
  the galaxy!