Across
- 2. a gigantic explosion in which a massive star collapses and throws its outer layers into space.
- 4. space and all the matter and energy in it.
- 8. the brightness of a star as seen from Earth.
- 11. all of the frequencies or wavelengths of electromagnetic radiation.
Down
- 1. Hertzsprung-Russell diagram a graph that shows the relationship between a star’s surface temperature and absolute magnitude.
- 3. a measure of how bright a star would be if it were seen from a standard distance.
- 5. a star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons.
- 6. a large cloud of gas and dust in interstellar space; a region where stars are born.
- 7. the distance that light travels in a year; about 9.46 trillion kilometers.
- 9. a small hot dim star that is the left over center of an old sun like star.
- 10. a collection of stars, dust, and gas bound together by gravity.
- 12. the actual brightness of an object such as a star.