| A | B |
|---|
| elliptical galaxy | galaxy that may vary in shape from nearly spherical to flat |
| binary star | member of a double star system |
| spiral galaxy | galaxy that is shaped like a pinwheel |
| constellation | group of stars that form a pattern |
| galaxy | huge collection of stars |
| nova | star that suddenly increases in brightness in just a few hours or days |
| nebula | massive cloud of dust and gas between stars |
| spectroscope | instrument that breaks up light into its characteristic colors |
| quasar | distant object that gives off mainly radio waves and x-rays |
| spectrum | band of colors formed when light passes through a prism |
| gravity | force of attraction between objects |
| red shift | shift toward the red end of the spectrum when a star is moving away from the Earth |
| big-bang theory | theory that states that the universe began with an explosion of matter and energy |
| Doppler effect | apparent change in the wavelength of light |
