National Aeronautics and Space Administration

1. 1. A spectrum of a star can be summed up as
   
   All the photons from the star that we detect.
   The energy of the photons from the star that we detect.
   The change in frequency of each photon from the star that we detect.
   The absorption of photons by the star.
   The emission of photons by the star.
   
   
2. A graphical representation of the Sun's visible spectrum
   
   is misleading.
   is exactly the same as seeing Sunlight through a prism.
   shows more information than Sunlight through a prism.
   shows less information than Sunlight through a prism.
   can be made from any data.

Remember that a spectrum is a graph of the emission from a source as a function of energy. A spectrum seen by passing light through a prism will show what colors or energies are emitted. A graphical representation shows how much emission is at each energy.

Learn more about what spectra can tell us

Use this technique to solve for M31's velocity

Return to the beginning and try another approach.