Location of S bursts at two separate frequencies. a) LOFAR 4 s dynamic spectrum showing negatively and positively drifting S bursts. The white line marks the timestamp in the images below. b) SDO/AIA 171 Å image at 11:25:11 UT and the overlaid LOFAR source of the negative drifting S burst at a frequency of 64−65 MHz at the time marked by the white line in a). c) SDO/AIA 171 Å image 11:25:11 UT and the overlaid LOFAR source of the positive drifting S bursts at a frequency of 51−52 MHz at the time marked by the white line in a). An animation of the temporal evolution is available in the online edition.