Sensitivity study for tau Cet e. Top row: F_p∕F_⋆-Δθ diagrams in which all orbital parameters remain fixed (as given in the corresponding title) except for the parameter indicated in the legend, which varies within its upper and lower uncertainties as quoted in the input catalogue (Table D.1). When any of the orbital parameters is unknown, we fix it to i = 90°, e = 0, or ω_p = 180° for this sensitivity study. Lines with intermediate colours correspond to orbital realizations with intermediate values of that parameter. A total of 100 orbital realizations are shown. Bottom row: intervals of α_obs that would be accessible for each of the orbital realizations in the panel above, using the same colour code. The optimistic CGI configuration is assumed.