Across
- 1. cooler area on surface
- 3. bright center of distant galaxy
- 6. a trillion million
- 8. hottest layer of atmosphere
- 9. collapsed core of a high mass star
- 11. start of explosion
- 12. fusion of h2 and he
- 15. collapsed neutron star, no light
- 16. squeezing atoms together
- 17. the raisins spread apart as the bread rises
Down
- 2. loop of gas
- 4. young stars in the arms
- 5. apparent shift
- 7. warm rises and cool sinks
- 10. tells us Galaxy are moving away
- 13. cloud of gas and dust
- 14. stream of charged particles