| A | B |
|---|
| spectral lines | fine, dark lines on a star's spectrum |
| spectral analysis | tells you which elements are in that star |
| energy flux | rate of energy flow out of a star |
| continuous spectrum | produced by a hot object; no spectral lines |
| emission spectrum | produced by a hot gas |
| absorption line spectrum | produced when there is a cool gas in front of a hot source |
| atomic number | number of protons in the nucleus |
| ionization | atom has missing or extra electrons |
| transition | electrons jump from one energy level to another |
| quantum mechanics | a branch of physics dealing with photons and subatomic particles |
| ground state | lowest level of electron in an atom |
| blueshift | spectrum of an object moving towards you |
| redshift | spectrum of an object moving away from you |
| radial velocity | speed of a star in motion along our line of sight, or "radius" between Earth and that star |
| proper motion | perpendicular motion of a star to the Earth |
| Vega's blueshift | Vega is approaching us |
| Barnard's Star | one of the closest stars to Earth |
| photon absorbed by atom | electron jumps up to a higher orbit |
| photon given off by atom | electron jumps down to a lower orbit |
| spectral lines occur | when an electron jumps from one energy level to another |
