unit 5

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Across
  1. 2. – clouds of dust and gas; site of star formation; remains of dead or dying stars
  2. 3. which began and is still expanding
  3. 4. and color of stars
  4. 5. – total amount of light (energy) emitted by a star or other celestial body
  5. 8. – the measure of the observed visible brightness of a star
  6. 11. Way galaxy – the galaxy which contains our Sun and its solar system, including Earth
  7. 13. microwave background – electromagnetic radiation that remains from the Big Bang and early stages of
  8. 14. – observations of galaxies moving away from each other and our own Milky Way galaxy
  9. 15. – a scientific theory concerning the early development and shape of the universe from a dense
Down
  1. 1. diagram – a diagram that shows the relationship between the brightness, surface
  2. 6. universe
  3. 7. – a region in space where gravity is so strong that even light cannot escape
  4. 9. and helium gas
  5. 10. – a system of stars and associated matter held together by gravitational attraction
  6. 12. – luminous globe of gas which produces its own heat and light by nuclear reaction made of mostly