TITLE: GCN CIRCULAR NUMBER: 15201 SUBJECT: GRB 130907A: T21 optical observations DATE: 13/09/08 22:35:10 GMT FROM: Veli-Pekka Hentunen at Taurus Hill Obs,A95 Veli-Pekka Hentunen, Markku Nissinen, Harri Vilokki and Tuomo Salmi (Taurus Hill Observatory, Varkaus, Finland) report: We have detected GRB 130907A optical afterglow at iTelescope observatory T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and FLI-PL6303E CCD. Six unfiltered images and seven photometric R filter images with 300 sec were made. The afterglow was detected at the following position RA 14:23:34.06 and DEC +45:36:27.1 J2000. The following magnitudes were obtained from the observations using NOMAD1 1356-0257141 (R=15.220) as a comparison star: Tmid(h)+T0 Filter Exp. time Mag Mag err. 4.70 unfiltered 3x300 20.00CR 0.49 5.22 R 7x300 20.06R 0.47 5.77 unfiltered 3x300 20.36CR 0.47