how many astronomical units away is alpha centauri
The third star, which may or may not be part of the system, is Proxima Centauri. It is about 4.22 light-years from Earth and is the closest star other than the sun. Alpha Centauri A and B orbit a common center of gravity every 80 years.The average distance between them is about 11 astronomical units (AU) â about the same distance as the sun is to Uranus.These stars are an average of 4.3 light-years from Earth.lpha Centauri A and B orbit a common center of gravity every 80 years. The average distance between them is about 11 astronomical units (AU) â about the same distance as the sun is to Uranus.