| A | B |
|---|
| electromagnetic spectrum | Radio waves, microwaves, infrared radiation, visible light, ultraviolet light, x-rays, gamma rays |
| visible light spectrum | Red, orange, yellow, green, blue, indigo, violet |
| Doppler Effect | The apparent change in wavelength from a source which could be visible light |
| What happens to the wavelengths of light when an object in space is moving toward Earth | The wavelengths decrease in length |
| What happens to the wavelengths of light when an object in space is moving away from Earth | The wave length increases in length |
| blue shifting | When an object in space is moving toward Earth |
| red shifting | When an object in space is moving away from Earth |
| characteristics used to classify stars | Color, size, brightness, chemical composition, and temperature |
| What does a stars color reveal | its surface temperature |
| What are the colors: hottest stars | blue-white |
| What are the colors: coolest stars | red-orange |
| medium-sized star | size of our sun |
| Very large stars | giants and supergiants stars |
| Very small stars | white dwarf and neutron stars |
| chemical composition of most stars | 73% hydrogen, 25% helium |
| brightness of stars depends on | size and temperature |
| apparent brightness | a stars brightness as it is seen from Earth |
| absolute brightness | the brightness a star would have if it were a standard distance from |
| light-years | unit used by astronomers to measure distances between stars |
| distance light travels in one year | light-year |
| parallax | used to measure distance to nearby stars |
| Use of Hertzsprung-Russell Diagram | to classify stars and to understand how stars have changed over time |
| 90% of all stars | main-sequence |
| Hertzsprung-Russell Diagram compares | surface temperature and absolute brightness |
