Thus, a more massive star uses up its hydrogen more rapidly than a less massive star. It is the mass of a star that determines its brightness, its temperature, and how fast it uses fuel. High mass stars are brighter, hotter, bluer, and have shorter lives than lower mass stars such as the Sun. The Sun is a main sequence star of midrange mass, so it has a theoretical ending of contracting to a white dwarf that slowly cools to a black lump of carbon. The Milky Way galaxy is believed to have a spiral shape, similar to the Andromeda galaxy.
Most stars appear to be normal, mature stars that are using their nuclear fuel at a steady rate.
These are called main sequence stars, as opposed to the other groups that represent stars somewhere else in their life cycle.