In a universe of billions of stars in billions of galaxies, how can we identify them? Each star has a name, a color, a temperature, and a luminosity value. Luminosity is compared to the Sun's luminosity such that a value greater than 1 means it is that many times the Sun's luminosity. A value less than one means it is that fraction of the Sun's value. Become familiar with the stars and write down what you are noticing. What general observations can you make of all of the stars?