Across
- 2. hydrogen nuclei fuse to form helium
- 6. expanded massive star
- 7. explosion triggered by the collapse of a super red giant
- 8. expanded smaller star running out of hydrogen
- 9. heaviest element formed by fusion before a supernova
- 11. object with gravity so strong even light cannot escape.
- 12. inward force causing a star to collapse
- 13. star that has cooled and stopped releasing heat
Down
- 1. collapsed star after helium fusion stops
- 3. long stable period of a star
- 4. star made of densely packed neutrons
- 5. early star reaching millions of degrees
- 10. cloud of dust and hydrogen gas