All stars are not the same distance away. Obviously, a star which is far away will appear dimmer than a similar star which is closer. We adjust for the distance of stars by giving stars an absolute brightness . This is because stars have different temperatures. Really hot stars are blue or white-hot.
Cool stars are red or redish-orange in color.
This classification system is called a spectral class system . Using the list of Bright Stars in Table 1 and the list of Near Stars in Table 2, plot their absolute magnitude vs. spectral class on the attached graph. Use different colors for the near stars and for the bright stars. Write your answers using sentences. Our star, the Sun, is a G2 spectral class star with an absolute magnitude of 4.8 .