Rapidly rotating stars are celestial bodies that spin on their axes at high speeds. This rapid rotation can cause the star to become oblate, meaning it bulges at the equator and flattens at the poles. The rotation affects the star's temperature and brightness, often leading to increased energy output. These stars can also exhibit unique phenomena, such as strong magnetic fields and intense stellar winds. Examples of rapidly rotating stars include Be stars, which are known for their emission lines and are often surrounded by a disk of gas. Understanding these stars helps astronomers learn more about stellar evolution and dynamics.