Spatial and temporal evolution of the chromospheric burst. The top left and bottom right panels mark the beginning and end of the heating event. The other two panels show intermediate stages. Boxes a–f are used to compute the average intensities plotted in Fig. 3. The outer to inner contours enclose the regions with intensities of (0.5, 0.7, 0.9) × I_max in the ribbon-like feature. Here, I_max is the intensity maximum in the respective SuFI snapshot. The arrows point to loop-like features associated with the burst. See Sect. 3 for details. The entire time series of this event is available as an online movie.