Regulus is a multiple star system consisting of at least four stars. Regulus A is the brightest star in the constellation Leo. It is a much larger star than our own sun. Regulus A has nearly 350 times as much energy as our sun. It is much hotter than our sun, with a surface temperature that averages about 12,000 K (roughly 21,000 degrees F). It is 77 light years away. Regulus is likely only a few hundred million years old, but it is rapidly approaching its own death.