Histograms for the IC (left panels) and for Δχ² (right panels) in the case of no-planet simulations. The upper panels consider the 5 yr mission, the lower panels the 10 yr mission. Leftpanels: green solid lines, WAIC; red dashed lines, AIC; blue dotted lines, BIC; the vertical dashed lines show the IC thresholds for weak and strong evidence according to Jeffreys’ scale. Right panels: solid and dashed curves show χ² distributions with the dof reported in the legend. The empirical density does not follow a χ² distribution with the nominal number of dof (7, solid red line). It can however be approximated, by a χ² distribution with a larger number of dof: 11 dof for the 5 yr mission, 15 dof (or 16 dof for Δ χ² ≳ 30) for the 10 yr mission.