The Types of Stars and Their Sizes

The Types of Stars and Their Sizes
On this H-R diagram, stellar luminosities are plotted against the surface temperatures of stars. The dashed diagonal lines indicate stellar
radii. For stars of the same radius, hotter stars (corresponding to moving from right to left on the H-R diagram) glow
more intensely and are more luminous (corresponding to moving upward on the diagram) than cooler stars. While individual
stars are not plotted, we show the regions of the diagram in which main-sequence, giant, supergiant, and white dwarf
stars are found. Note that the Sun is intermediate in luminosity, surface temperature, and radius; it is very much a middle-of-
the-road star.