Supergiants

Supergiants are the most massive and luminous stars in the universe. Imagine that if the Sun were a pea, a red supergiant would fill the space all the way to Jupiter's orbit. Blue supergiants (classes O, B) are extremely hot, young, and massive stars that burn fuel rapidly. Yellow supergiants (classes F, G) represent a brief transitional phase. Red supergiants (class M) are cooler but emit vast amounts of energy due to their immense surface area. A key relation exists: the higher the mass, the higher the core temperature and pressure, leading to greater size, luminosity, and a violent end as a supernova.