Components of the Universe

5. different colors of light emitted based on the chemical composition of the light source
6. the number of times a wave passes a certain point in a given amount of time
8. a diagram that shows the relationship between the brightness, surface temperature, and color of stars
11. clouds of dust and gas; site of star formation; remains of dead or dying stars
12. a tool for observing spectral lines
13. the measure of the observed visible brightness of a star
14. a system of stars and associated matter, held together by gravitational attraction

1. all of space and its contents
2. a measure of how bright a star appears as seen from Earth
3. distance from any one point on a wave to a corresponding point on the next wave; crest to crest or trough to trough
4. a classification of all forms of radiation by wavelength and frequency; used to study components of the universe
7. a scientific theory concerning the early development and shape of the universe from a dense state which began and is still expanding
9. a measure of how bright a star really is, if all stars were the same distance from Earth
10. total amount of light (energy) emitted by a star or other celestial body
12. luminous globe of gas which produces its own heat and light by nuclear reaction