GCN Circular 22792
C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large collaboration report: The 2-m Liverpool Telescope automatically began observing Swift GRB 180618A (LaPorte et al. GCN 22790) on June 18, 00:46:30 UT (197 s since the GRB trigger time) with the RINGO3 polarimeter and the IO:O camera in the SDSS-R filter. The optical counterpart identified by Swift-UVOT is clearly detected with r'=19.36 +- 0.05 mag in a 6x10s exposure at a mid time of 36.3 minutes post GRB, as calibrated against nearby SDSS objects.