Question: is alpha centauri a planet?
Answer: Key Facts & Summary. Alpha Centauri was discovered in 1915, while it's only confirmed planet, Proxima Centauri b, was discovered in 2016 and it is the closest exoplanet to us. The two main stars Alpha Centauri A and B form a binary pair and are 4.3 light-years away from Earth. They are also named Alpha Centauri AB.