Yellow Hypergiant

A yellow hypergiant is a massive star with an extended atmosphere,a spectral class from late A to early K, an initial mass of as much as 20–50 solar masses, but having lost as much as half that mass. They are amongst the most visually luminous stars, with absolute magnitude (M_V) around −9, but also one of the rarest with just a handful known in our galaxy. Yellow hypergiants occupy a region of the Hertzsprung-Russell diagram known as the "Yellow Evolutionary Void", a region where relatively few stars are found and where those stars are generally unstable.