Blue dwarf (red-dwarf stage)

A blue dwarf is a theoretical type of star that would occur at the end of the main sequence phase of red dwarfs in the far future. Red dwarfs are the smallest and coolest type of main-sequence stars. They burn their hydrogen at a low rate and can have lifespans that last for tens to hundreds of billions of years, far exceeding that of larger stars, which typically evolve into more massive stages like red giants.