TITLE: GCN CIRCULAR NUMBER: 14968 SUBJECT: Fermi394416326: FTN detection DATE: 13/07/03 10:02:32 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (Ferrara U.), C.G. Mundell, I.A. Steele (LJMU), on behalf of a large collaboration report: On 2013 July 03 (09:03:30 UT) we began observing the field of the possible optical afterglow of Fermi394416326 (Singer GCN Circ. 14967) with the 2-m Faulkes Telescope North in Hawaii. Observations were carried out using the BVRi filters. We clearly detect the optical counterpart discovered by Singer et al. with the following magnitudes Time from GRB Filter Exposure[s] Magnitude (days) ---------------------------------------------------- 1.38 i' 100 18.61 +- 0.07 1.38 R 120 18.46 +- 0.05 ---------------------------------------------------- The calibration was performed using the i' magnitudes of SDSS catalogue field stars and the R magnitudes obtained using the transformations by Jordi et al (2006).