Our Sun is the closest start to us. It is only 93 million miles away! The next closest stars are members of a star system called Alpha Centauri. Alpha Centauri is a triple star system that is 4.3 light years away from Earth. The three stars are called Alpha Centauri A, B, and C. Alpha Centauri C is also known as Proxima Centauri because it is usually the closest of the three to Earth.