Path-time diagrams of the three type-III radio bursts as obtained from the observed (s_obs ), fundamental (s_f) and harmonic (s_h) emission regions in the plane of sky according to Table 2. The sources propagate with increasing speed. The error in time is either one or two time steps of 0.94 s depending on how clearly the image of the burst’s onset could be distinguished. The statistical error of s is about 0.01 R_⊙ and hidden by the marker.