Across
- 4. A name of a type of nebula
- 5. The last one was recorded in our galaxy in 1604
- 8. A collection of galaxies
- 10. Stars spend most of their lives as these
- 11. What hydrogen fuses into
Down
- 1. When helium fuses into carbon and oxygen
- 2. When the gravitational force compressing the star is balanced to the radiation pressure from photons being emitted during fusion
- 3. The limit at which the mass of a core is less than 1.4 times the mass of the Sun
- 6. Stars with a density of approximately 4x10^17kg/m^3
- 7. Giant clouds of dust and gas
- 9. A hot and dense sphere of dust and gas