Look for the "three systems" section in the OP. You don't place new planets in a star system. You take the place holder planets and expand on them. 

There's a tidally locked planet around proxima centauri. However, another player who was on chatzy also wants that planet. When the OOC is up i'll have to pick between your app and wasd's app since I assume you are referring to a eye ball earth.

Or alternatively you could potentially share the planet with wasd.