a) X-ray image of a C4 flare that peaked at 2021-11-01 23:39 UT as observed at Earth. The red and black show the XRT Be-thick filter image, and the white lines show 30%–90% contours of the STIX 6 – 10 keV emission. The STIX image was produced by forward-fitting an elliptical Gaussian, and its size has been corrected for the difference in observer distance. Despite the different temperature responses and imaging techniques of the two instruments, the source areas agree very well. b) Light curves of the STIX 6 – 10 keV (solid blue) and XRT Be-thick (dashed orange) emission. The source size in panel a) agrees despite a slightly different evolution of the light curves.