Why are they called white dwarfs?
They actually are white, although as they cool they become redder and redder. However, recently astrophysicists such as Brad Hansen and Didier Saumon have shown that once they cool below 4,000 Kelvin they begin to turn bluer. This effect has been confirmed with observations. The term “dwarf” refers to what astronomers call the “luminosity class” of an object and is meant to indicate that in the range of luminosities that stars posess dwarfs rank relatively low. In this sense, the Sun is also a dwarf star.
