Across
- 2. a small hot dim star that is left over center of an old sun like star
- 4. a collection of stars, dust, and gas bound together by gravity
- 7. space and all the matter and energy in it
- 9. the actual brightness of a star
- 10. the brightness of a star as seen from Earth
- 12. the distance that light travels in a year
Down
- 1. a gigantic explosion in which a massive star collapses and throws its outer layers into space'
- 3. all of the frequenciesor wavelengths of electromagnetic radiation
- 5. a measure of how bright a star would be if it were seen from a standard distance
- 6. a star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons
- 8. where stars are born
- 11. Hertzsprung Russell diagram a graph that shows the relationship between a star's surface temperature and absolute magnitude