| A | B |
|---|
| binary stars | two star systems |
| constellation | a group of stars |
| nova | a star that suddenly increases in brightness for a few hours |
| nebula | a big cloud of dust and gas |
| Milky Way | the name of the galaxy we live in |
| spiral | the type of galaxy we live in |
| spectroscope | an instrument used to see the color of distant stars |
| spectrum | the band of colors formed when light passes through a prism |
| red shift | a star moving away from the earth |
| blue shift | a star moving toward the earth |
| Big Bang | theory of how the universe was formed |
| open universe | expands forever |
| closed universe | expands and then gets smaller due to gravity |
| quasar | a star-like object that gives off radio waves |
| apparent magnitude | how bright a star appears from Earth |
| absolute magnitude | the amount of light a star actually gives off |
| prominence | huge bright loops of gas |
| solar flare | bursts of light |
| sunspots | dark areas on the sun |
| black hole | a cosmic vacuum cleaner |
