Stars, Galaxies, and Universes

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Across
  1. 1. Hypothetical form of energy, may make up as much as 71% of the energy in the universe.
  2. 4. This is so dense that light cannot escape the gravity.
  3. 10. Nuclear fusion in the star's core produces helium from hydrogen.
  4. 11. Ball of glowing gas at very high temperature.
  5. 13. Egg-shaped rotating galaxy.
  6. 14. Galaxies that are not spiral or elliptical.
Down
  1. 2. A large red-colored start that is collapsing inward on itself.
  2. 3. The leftover material in the core after a supernova explosion.
  3. 4. Two stars orbiting each other.
  4. 5. Groups of up to a few thousand stars that are loosely held by gravity.
  5. 6. All of the star systems, galaxies, gas and dust.
  6. 7. The study of the universe.
  7. 8. Biggest group of stars; may contain hundreds of thousands of stars.
  8. 9. Matter that we can't see but know exists; does not emit electromagnetic radiation.
  9. 12. Our galaxy