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