  We examine the formation of planets around binary stars in light of the
recently discovered systems Kepler 16, 34 and 35. We conduct hydrodynamical
simulations of self gravitating disks around binary systems. The selected
binary and disk parameters are chosen consistent with observed systems. The
disks are evolved until they settle in a quasi-equilibrium and the resulting
systems are compared with the parameters of Kepler 16, 34 and 35. We find a
close correspondence of the peak density at the inner disk gap and the orbit of
the observed planets. We conclude, based on our simulations, that the orbits of
the observed Kepler planets are determined by the size of the inner disk gap
which for these systems results from the binary driving. This mediates planet
formation either through the density enhancement or through planetary trapping
at the density gradient inversion in the inner disk. For all three systems the
current eccentricity of the planetary orbit is less than the disk eccentricity
in the simulations. This, together with the long term stability of the orbits
argues against in situ formation (e.g. a direct collapse scenario of the
material in the ring). Conducting additional simulations of systems with a
wider range of parameters (taken from a survey of eclipsing binaries), we find
that the planet semi-major axis and binary eccentricity in such a scenario
should be tightly correlated providing an observational test of this formation
mechanism.
