Across
- 2. A gigantic explosion in which a massive star collapses and throws its outer layers into space
- 4. A measure of how bright a star would be as seen from standard distance
- 7. The actual brightness of an object such as a star
- 8. A small hot dim star
- 10. a star that has collapsed under gravity
- 12. Space and all the matter and energy in it
Down
- 1. the brightness of a star as seen from Earth
- 3. All of the frequencies or wavelengths of electromagnetic radiation
- 5. A collection of stars, dust, and gas bound together by gravity
- 6. the distance light travels in about a year
- 9. Hertzsprung-Russel diagram
- 11. A large cloud of gas and dust