A dwarf star, ranging in mass from one-tenth to one-half the mass of the sun, whose relatively cool surface temperature makes it appear red-orange in color.
A star that is cooler on its surface, smaller, and of fainter luminosity than the sun.
A small, dim star with relatively cool surface temperatures, positioned to the lower right on the main sequence in the Hertzsprung-Russell diagram. Red dwarfs, at about 0.1 to 0.5 solar mass, consume their nuclear fuel very slowly and live for about 100 billion years. Although they are difficult to see, they are so long-lived that they are likely the most abundant type of star; of the 30 nearest stars to Earth, 21 are red dwarfs, including the closest star, Proxima Centauri.