Muh Joos shills starting early today.
You're confusing Alpha Centauri with Proxima Centauri. Alpha Centauri is the closest Star System, consisting of 3 stars and possibly a few planets. Proxima Centuari is also called Alpha Centauri C, and is the closest of the three individual stars in the system.
Yes the definition of a planet is wandering star, but that doesn't mean they are literally stars. they appear that way to the unaided eye, like the ancient greeks. .
Sorry, it's hard to tell who the Flattards are or aren't sometimes…