ReleaseDate
This parameter has to be used
together with the ReleaseRadius
parameter. They both are relative to planet 0 only, and they can be used to
specify a forced migration (with constant, arbitrary da/dt). The planet 0 trajectory is forced for 0 < t < ReleaseDate, and is
such that at t=ReleaseDate,
the planet semi-major axis is equal ReleaseRadius. At t=0, the planet semi-major axis is
the one indicated in the planet configuration file (see PlanetConfig). Between t=0 and t=ReleaseDate, the semi-major axis
of planet 0 is an affine
function of time. Its angular speed is the Keplerian one corresponding
to its instantaneous semi-major axis. For t>ReleaseDate, the planet
migrates according to the torque exerted by the disk (its orbit is no
longer forced).