Across
- 5. How bright an object appears from earth
- 7. hot dense slowly cooling sphere of carbon
- 8. true brightness of an object
- 10. explosion that destroys a star
- 12. huge collection of stars, gas, and dust
- 14. object where gravity stops light from escaping
- 16. layer-hot gasses move upward and then cool
- 19. graph that plots luminosity v. temperature
Down
- 1. instrument that spreads light in wavelengths
- 2. dense core of neutrons after supernova
- 3. matter that emits no light at any wavelength
- 4. Distance light travels in one year
- 6. apparent surface of a star
- 9. shell of cooler hydrogen above core
- 11. fusion when atoms combine and give off energy
- 13. orange red layer above photosphere
- 15. cloud of gas and dust
- 17. large sphere of hydrogen gas held by gravity
- 18. wide outermost layer of star atmosphere