Life Cycle of Stars

123456789101112131415161718192021
Across
  1. 4. The stars heats up and hydrogen is converted to helium
  2. 9. These stars use up their fuel more quickly
  3. 10. forms from the outer layers of hydrogen and helium that are cast off when a red giant becomes a white dwarf
  4. 13. These stars form from small supergiants
  5. 17. The brightness of a star's light is called
  6. 19. The most massive stars form ____ in their core
  7. 20. Huge cold clouds of gas and dust
  8. 21. A white dwarf that has cooled
Down
  1. 1. When a massive star runs out of hydrogen, it turns into this type of star
  2. 2. These stars have no fuel, but glow from leftover energy
  3. 3. Stars spend most of their lives here as long as hydrogen fuses into helium
  4. 5. A star that is more massive than the sun may live only about ten _____ years
  5. 6. These stars are rich in hydrogen
  6. 7. A place in space where gravity is so great that light can't escape
  7. 8. this
  8. 11. How long a star lives depends on its
  9. 12. The earliest stage of a star's life in which the contracting cloud heats up and
  10. 14. Stars that have less mass then the sun can live up to ____ billion years
  11. 15. The explosion of a large star that causes heavier elements to form
  12. 16. medium-mass star will live for about ___ billion years
  13. 18. Once medium-sized stars run out of nuclear fuel, the star becomes a