Optical imaging of eRASS1 J050129.5−073309. Top panel: combined g-, r-, and z-band LS DR10 (DECals) images centered on the source. Middle panel: red-green-blue image of the residuals after subtracting three point sources (the star and the lensed images) with GALFIT. We mark the lensed images of the quasar with black (top) and white (bottom) squares. The Gaia position of the star is marked with a white (top) and black (bottom) diamond. The LS DR10 position of the lensing galaxy is marked with a red and black triangle in the top and bottom panels, respectively. We also annotate the position of the likely lensed arcs and the lensing galaxy. Bottom panel: individual LS DR10 g, r, i, and z residual images of the lensing galaxy and arcs after point-source subtraction of the lensed quasar images and the foreground star (green circles). The scale bars have an angular size of 5″.