How does Proxima Centauri play into this? I am assuming it isn't a trinary star system, but they mention it being (roughly) the same distance away in the same d

How does Proxima Centauri play into this? I am assuming it isn't a trinary star system, but they mention it being (roughly) the same distance away in the same direction. Also, are there planets in the binary Alpha Centauri system? Do they orbit the common center of mass that the two stars orbit?