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