Across
- 4. A large grouping of stars.
- 6. The amount of light emitted by a star.
- 7. a very large cloud of dust and gas that exists in outer space.
- 9. a cataclysmic explosion caused when a star exhausts its fuel and ends its life.
- 11. A compressed core of an exploded star made up almost entirely of neutrons.
- 12. a small dense star.
- 13. A spinning neutron star that emits energy along its gravitational axis. This energy is received as pulses as the star rotates.
- 14. core of a supermassive star that remains after a supernova; has gravity so strong that even light can’t escape.
- 15. center of an object.
- 16. a bright object in space that has a tail of gas and dust.
- 18. a small group of about two dozen galaxies of which our own Milky Way galaxy is a member of.
- 19. a natural or artificial body in orbit around a planet.
- 20. The outer part of the Sun's atmosphere.
Down
- 1. A stage in the evolution of a star when the fuel begins to exhaust and the star expands to about fifty times its normal size. The temperature cools, which gives the star a reddish appearance.
- 2. a giant ball of hot gas that creates and emits its own radiation through nuclear fusion.
- 3. a star and the planets that go around it.
- 5. combining of two atomic nuclei to produce one larger nucleus, with the release of nuclear energy.
- 8. A system of two stars that revolve around a common center of gravity.
- 10. the proportion that of the material of a star that is in elements other than hydrogen or helium.
- 17. The degree of brightness of a star or other object in the sky.