Spectral time map based on 281 RGS spectra extracted from adjacent 200 s time intervals from the 2021d55.6 observation. The main panel shows the spectra with wavelength from left to right, time from top to bottom, and colours representing flux following the (non-linear) bar in the top right panel along the vertical flux axis. The dashed horizontal lines and shadings with the same colours in the bottom right panel indicate time intervals from which the spectra shown with the same colour shadings in the top left panel were extracted. The brown dotted line in the light curve panel in the bottom right represents the hardness light curve extracted from the pn where hardness is scaled to fit into the graph while varying between values −0.580 and −0.397.