Across
- 4. the disance light travels in one year
- 5. a huge collection of stars
- 7. complete spectrum of light
- 10. one crest and one trough
- 11. the top of a wave
- 12. the length of a wave
- 13. the rate he waves peak passes by a point
Down
- 1. refers to a portion of the entire electromagnetic spectrum
- 2. a star that changes in brightness
- 3. the amount of waves per second
- 6. apparent shift in position of a star
- 8. the amount of light that reaches us
- 9. the bottom of a wave