The Life Of Stars

123456789101112
Across
  1. 2. a small very dense star that is typically the size of a planet. It is formed when a low-mass star has exhausted all its central nuclear fuel and lost its outer layers as a planetary nebula
  2. 3. a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass
  3. 5. about the size of our sun
  4. 6. the nebulosity surrounding a star
  5. 7. a ring-shaped nebula formed by an expanding shell of gas around an aging star
  6. 10. a region of space having a gravitational field so intense that no matter or radiation can escape
  7. 11. the star within our solar system that gives life on earth
  8. 12. any luminous object in the sky is massive and remote
Down
  1. 1. Any star which is larger than 8 solar masses during its regular main sequence lifetime
  2. 4. aging giant star which has consumed its core's supply of hydrogen fuel. Helium has accumulated in the core, and hydrogen is now undergoing nuclear fusion
  3. 8. a celestial object of very small radius (typically 18 miles/30 km) and very high density, composed predominantly of closely packed neutrons
  4. 9. a very large star of high luminosity and low surface temperature. They are thought to be in a late stage of evolution when no hydrogen remains in the core to fuel nuclear fusion