TITLE: GCN CIRCULAR NUMBER: 14468 SUBJECT: GRB 130427A: Zadko observatory - Gingin optical observations DATE: 13/04/27 17:43:48 GMT FROM: Alain Klotz at IRAP-CNRS-OMP B. Gendre, A. Klotz (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA), M. Boer, K. Siellez, H. Dereli , O. Bardho (UNS-CNRS-ARTEMIS-OCA), A. Williams (PO-UWA), R. Martin (PO-UWA) report: We imaged the field of GRB 130427A detected by SWIFT (trigger 554620) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia. The observations started 3.44h after the GRB trigger (the event occured during the local afternoon). The elevation of the field increased from 23 degrees above horizon and weather conditions were good. We detect the optical couterpart discovered by Elenin et al. (GCNC 14450). The unfiltered images are analyzed regarding the R magnitude of star catalogues. The preliminary light curve is: Tstart Tstop Rmag 1sig (mins) (mins) 207 219 15.50 0.1 220 232 15.54 0.1 238 250 15.37 0.1 252 264 15.56 0.1 265 277 15.51 0.1 304 319 15.58 0.1 447 450 16.27 0.2 Magnitudes are not corrected for galactic dust extinction. This message may be cited.