a) Zoom of the last image in Fig. 2. The bi-sector of the tail is indicated by a white line. Predicted positions of the nucleus at mid-exposure for the last 10 min are shown as red dots (ending with a cross) and indicate the trajectory. The arrow points toward Sun center. The tail is offset from the trajectory and not parallel to it. b) A model dust tail can reproduce the observation. The line of green dots marking the tip points of the higher-level contours resembles the tail axis, if we assume a violent dust emission burst ≈8.5 h prior to perihelion transit followed by a sharp decrease of the dust production.