Vocab 29.2

5. distance between two identical points on a wave
8. every particle attracts every other particle in the universe with a force that is directly proportional to the product of their mass
10. energy output from the surface of a star per second
11. different in height between the crest and the trough
12. lowest point on a wave
14. shift in position caused by the motion of the observer
17. way to organize stars
18. when electromagnetic radiation from an object undergoes an increase in wavelength
19. decrease in wavelength, with a corrosponding increase in frequency of an electromagnetic wave
20. small, blue star

1. groups of stars that look like everyday objects; animals and mythological characters
2. how bright a star appears
3. region on the HR diagram where most stars fall
4. large star with high luminosity and low surface temperature
6. heat energy
7. how bright a star would appear if it were placed at a distance of ten parsecs
9. distance that light travels in a year
11. almost dead star
13. two stars that are gravitationally bound together, they orbit a common center of gravity
14. unit larger than a light year
15. refers to the change in wave frequency during the relative motion between a wave source and its observer
16. highest point on a wave