Main Sequence stars run across the central portion of the Hertzsprung-Russell diagram, from cool faint stars in the lower right-hand corner to the hottest, brightest O and B stars in the upper left-hand corner. The white dwarfs, compact objects which are the endpoint of stellar evolution for low mass stars, are found below the Main Sequence, clustered in a band at small radii (roughly one-hundredth the radius of the Sun). In contrast, giant stars have evolved upward off of the Main Sequence, ballooning outward in size to large radii and an increased luminosity.

What does Stephen's Law tell us about stars with the same temperature, but different radii?