SCIENCE

1. a graph that shows the relationship between a star's surface temperature and absolute magnitude
5. the brightness of a star seen from earth
9. an apparent shift in the position of an object when viewed from different locations
10. a group of stars that looks like a ball and contains up to 1 million stars
13. a gigantic explosion in which a massive star collapses and throws its outer layers into space
15. a large, reddish star late in its life cycle
16. a region of space where stars are born or where stars explode at the end of their life
18. the distance that light travels in a year, about 9.5 trillion kilometers
20. the band of color produced when white light passes through a prism

2. the location on the HR diagram where most stars lie
3. a star that has collapsed under gravity to the point that the protons and electrons have smashed together to form neutrons
4. a group of stars that are close together relative to surrounding areas
6. a rapidly spinning neutron star that emits rapid pulses of radio and optical energy
7. the brightness that a star would have at a distance of 32.6 light years from earth
8. an object so massive and dense that even light cannot escape its gravity
11. the study of the origin, properties, processes, and evolution of the universe
12. a small, hot, dim star that is the leftover center of an old star
14. a collection of matter bound together by gravity
17. the theory that states the universe began with a tremendous explosion 13.7 billion years ago
19. a very luminous, starlike object that generates energy at a high rate