TITLE: GCN CIRCULAR NUMBER: 23311 SUBJECT: GRB 181010A: LCO Cerro Tololo observations DATE: 18/10/10 07:35:32 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy R. Martone, C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU), A. Cucchiara, D. Morris (U. of Virgin Islands) on behalf of a large collaboration report: We automatically began observing Swift GRB 181010A (Melandri et al. GCN 23309) with one LCO 1-m unit at Cerro Tololo from October 10, 06:02:54 UT (corresponding to 7.1 minutes from the GRB trigger time) with the SDSS r' filter. We clearly detect the optical counterpart reported by Swift-UVOT with r'=19.98 +- 0.12 mag from a 3x120s exposure at a mid time of 10.7 minutes post GRB, as calibrated against nearby Pan-STARRS objects.