Observation summary. Panel a: full FOV covered in the 17.4 nm band of HRI_EUV. The red box outlines the zoomed-in FOV shown in panel b. Both panels show the time-averaged normalized intensity (to the minimum and maximum in the area in panel b). Panel b: location of the cut (vertical black line) used in the time–distance plot displayed in Fig. 2 and the intensity–distance plot shown in Fig. 3. The cyan box (i) and the orange box (ii) outline the diffuse region and the bright point used in Fig. 4. The green box (iii) outlines the loop-like features shown in Fig. B.1 (see Sect. 3.1).