Letter class F average lifespan 2 million - 6 billion yrs Type Class of moderately sized main sequence star. Mass range 1.12–1.6 M☉ Temperature 6100–7200 K Average luminosity 1.64–7.31 L☉ Average radius 1.15 - 1.7 some examples Procyon A Polaris (the north star) Alpha Hydri
