Letter classification K average lifespan 15 billion yrs - 70 billion yrs Type Class of medium-small main sequence star Mass range 0.59–0.88 M☉ Temperature 3,930–5,270 K Average luminosity 0.079–0.46 L☉ Solar radius 0.7-0.96 radii examples Alpha Centauri B Kepler-442 Epsilon Eridani
