Across
- 5. about the size of earth but about a million times more dense than the sun
- 7. a group of single stars
- 8. the first stage of a stars formation
- 9. has all of space and everything in it
- 11. the universe formed in an instant billions of years ago by an explosion
- 12. the brightness if the star were a standard distance from earth
Down
- 1. the distance that light travels in one year
- 2. material from the star that expands into space
- 3. to look at or study
- 4. the brightness seen from earth
- 6. a scientific conclusion
- 10. large cloud of gas and dust containing an immense volume of material.