Variations (Δ) of the fitted parameters for different initial values of the semi-major axis of the planet c; each point corresponds to a different simulation. In this case, the input parameters (of planet c) are the parameters in Table 1 used to generate the exact transit times. The goodness of the fit has been color-coded so that good fits () have been plotted as blue points and bad fits () as open circles. The small gaps are due to the random sampling used to generate the grid in the semi-major axis a.