TITLE: GCN CIRCULAR NUMBER: 20006 SUBJECT: GRB 160925A: Kottamia R-band observation DATE: 16/10/06 23:05:13 GMT FROM: Gamal B. Ali at NRIAG G. B. Ali, Y. Hendy, A. Takey, N. Essam, and A. Essam (NRIAG, Egypt) report on behalf of the Kottamia collaboration: We observed the field of the Fermi GRB 160925A (trigger #496473540) with the 1.88m telescope of the KAO (Kottamia Astronomical Observatory), Egypt. The observation was performed in the Rc-band at the Newtonian camera (F4.8) and started at 2016-09-29 T19:58:17 UT (~4.08 day after the burst). We obtained several exposures in the Rc-band each one with 300s exposure time. We clearly detected the optical transient (Lipunov et al., GCN 19938; Guidorzi et al., GCN 19939). The following accurate photometry is obtained for the transient: UT (Start) Rc error* 2016-09-29T19:58:17 17.260 0.011 2016-09-29T20:03:31 17.232 0.011 2016-09-29T20:08:42 17.252 0.012 2016-09-29T20:13:53 17.326 0.013 2016-09-29T20:19:04 17.267 0.012 2016-09-29T20:24:15 17.223 0.011 2016-09-29T20:29:26 17.305 0.011 2016-09-29T20:34:37 17.281 0.012 2016-09-29T20:39:48 17.239 0.011 ---------------------------------------------------- (*) Poisson noise error only. The Photometric calibration is based on nearby USNO-B1.0 stars USNO-B1.0 R2 0750-0813981 13.69 0750-0813991 14.20 0750-0813958 14.93 0750-0813917 15.62 [GCN OPS NOTE(08oct16): Per author's request, the signature block and the appended copy of the 19947 circular have been removed.]