 According to theoretical simulations, even widely separated binary stars often disrupt the discs of rocky grains from which protoplanets form.On the other hand, other simulations suggest that the presence of a binary companion can actually improve the rate of planet formation within stable orbital zones by "stirring up" the protoplanetary disk, increasing the accretion rate of the protoplanets within.Detecting planets in multiple star systems introduces additional technical difficulties, which may be why they are only rarely found.