dwarf star, any star of average or low luminosity, mass, and size. Important subclasses of dwarf stars are white dwarfs (see white dwarf star) and red dwarfs. Dwarf stars include so-called main-sequence stars, among which is the Sun. The colour of dwarf stars can range from blue to red, the corresponding temperature varying from high (above 10,000 K) to low (a few thousand K).