TITLE: GCN CIRCULAR NUMBER: 32489 SUBJECT: GRB 220826A: Lesedi optical afterglow detection DATE: 22/08/26 18:59:01 GMT FROM: Simon de Wet at UCT S. de Wet (UCT) and D.B. Malesani (Radboud and DAWN/NBI) report: Following the detection of GRB 220826A by Swift and its X-ray and optical counterparts (Caputo et al., GCN 32484; Kuin et al., GCN 32488; Romanov F.P., GCN 32487), the 1m Lesedi optical telescope located at Sutherland, South Africa, obtained 600 s exposures in each of the g,r,i and z bands with the Mookodi low-resolution spectrograph and imager beginning at 17:27:09 UT, approximately 0.23 days post-trigger. We detect the optical afterglow to GRB 220826A in each image at the UVOT position with the following AB magnitude, calibrated to Skymapper flux measurements of a nearby star in the field: r = 21.48 +/- 0.16 Lesedi is built and operated by the South African Astronomical Observatory.