Its increasing density brings it steadily nearer degeneracy. For a star more massive than 0.08 M☉, fusion begins before degeneracy is reached, so the star begins its main sequence career. For a less massive star, degeneracy develops before hydrogen fusion begins. After the star becomes degenerate, the pressure supplied by its degenerate electrons doesn’t’ depend on temperature. The star stops contracting and begins to grow cooler and dimmer. Perhaps such and object shouldn’t be called a star at all, because it never generates a significant amount of nuclear energy. The term brown dwarf is often used to refer to objects that narrowly miss becoming nuclear stars.