Astronomy Crossword

4. Earth's pull on objects toward the center of the planet
5. Outbursts of light that occur in areas of sunspot activity
9. A different star after hydrogen runs out and is the outcome of a bigger star
10. Shows how fast galaxies are moving away from one another
12. Actual or true brightness of a star
14. Second densest object in universe
15. Lumonosity of stars as if they were seen from the same distance from the Earth
16. Distance between the earth and sun
17. Dark and cool spots on photosphere
19. Most dense object in whole universe

1. System containing millions of billions of stars that orbits a common mass and travel as a unit
2. Nuclear Reaction
3. Distance light travels in one year
6. How bright the star appears to an observer on Earth
7. AFter main sequence and a smaller star
8. After smaller nova shrink
11. The idea of matter and energy compressed into a single dense point that exploded into an ever expanding universe
13. Increased blasts that interfere with radio and T.V reception
14. Stars begin as cloud of dust and gas
18. After red giant
20. Outer layer of atmosphere