| A | B |
|---|
| spectrum | the band of colors produced when white light passes through a prism |
| apparent magnitude | the brightness of a star as seen from Earth |
| absolute magnitude | the brightness that a star would have at a distance of 32.6 light-years from Earth |
| light-year | the distance that light travels in one year; about 9.46 trillion kilometers |
| parallax | an apparent shift in the position of an object when viewed from different locations |
| red giant | a large, reddish star late in its life cycle |
| white dwarf | a small, hot, dim star that is the leftover center of an old star |
| H-R diagram | Hertzsprung-Russell diagram, a graph that shows the relationship between a star s surface temperature and absolute magnitude |
| main sequence | the location on the H-R diagram where most stars lie; it has a diagonal pattern from the lower right (low temperature and luminosity) to the upper left (high temperature and luminosity) |
| supernova | a gigantic explosion in which a massive star collapses and throws its outer layers into space |
| neutron star | a star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons |
| pulsar | a rapidly spinning neutron star that emits pulses of radio and optical energy |
| black hole | an object so massive and dense that even light cannot escape its gravity |
