TITLE: GCN CIRCULAR NUMBER: 18266 SUBJECT: GRB 150910A: LCOGT FTN afterglow observations DATE: 15/09/10 11:05:14 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy S. Dichiara, C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), A. Gomboc (U. Ljubljana), C. Mundell (U. Bath) on behalf of a larger collaboration report: The 2-m LCOGT Faulkes Telescope North in Hawaii began observing Swift GRB 150910A (Pagani et al. GCN 18264) on September 10, 09:33:19 UT (28 minutes after the burst trigger) with SDSS r and i filters. We clearly detect the optical afterglow (Pagani et al. GCN 18264; Zheng et al. GCN 18265) with the following magnitudes: Mid Time Exposure Filter Magnitude (min) (s) ------------------------------------------------------- 29.0 60 r' 16.60 +- 0.02 35.6 60 i' 16.42 +- 0.02 ------------------------------------------------------- Calibration is done against SDSS magnitudes of nearby stars.