Disturbance connection times as a function of the longitudinal separation angle from the eruption site for an expansion speed of 800 km s⁻¹ and varying α values among the different panels. The blue curves show the times that the disturbance connects to field lines for the first time, the solid black curves show the time that the disturbance connects at the same field lines at the solar surface. The coloured curves show the connection times when the disturbance has a specific Θ_Bn at the connected field lines. The dashed black curves show the time when Θ_Bn = 45° (oblique geometry). For the calculation of Θ_Bn, we assumed that the field lines are Parker spirals (Θ_Br ≠ 0°). The inset plot in each of the panels shows the propagating disturbance (coloured circles) for the different set of parameters used.