Across
- 4. contains only a few thousand stars
- 6. main sequence
- 10. not spiral nor elliptical
- 12. 2 atoms combine
- 13. big group of stars
- 14. two stars
Down
- 1. violent explosion
- 2. cannot see it
- 3. cosmological explanation
- 4. change of frequency
- 5. light cannot escape
- 7. egg shaped
- 8. ball of glowing gas
- 9. 71% of the energy
- 11. study on the universe