Well Anyone Who Watched Star Trek Knew THAT!
Scientists have posited the likelihood of rocky, Class M planets orbiting Alpha Centauri B. via The Speculist
Scientists in California carried out computer simulations that suggest Earth-like planets may be orbiting Alpha Centauri B.
At least some are likely to be in the so-called "habitable zone" at just the right distance from their parent star to allow oceans, lakes and rivers to form without freezing or boiling away. Such planets are the best candidates for supporting life as we know it.
Well duh. There is humanoid life on Alpha Centauri, seeded by The Preservers from Earth's Mediterranean basin. And Zefram Cochrane is from there.