Proxima orbits at a great distance from the inner pair of stars, around their center of mass. Proxima is also a small red dwarf star. This layout had to have be

Proxima orbits at a great distance from the inner pair of stars, around their center of mass. Proxima is also a small red dwarf star. This layout had to have been well-known by the time the book was written. This is perhaps similar to the pursuit of "unobtainium" in Avatar. Both just seem lazy.