TITLE: GCN CIRCULAR NUMBER: 14295 SUBJECT: GRB 130313A: Zadko observatory - Gingin optical observations DATE: 13/03/13 18:15:55 GMT FROM: Alain Klotz at IRAP-CNRS-OMP A. Klotz (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA), B. Gendre (IRAP-CNRS-OMP), M. Boer, K. Siellez, H. Dereli , O. Bardho (UNS-CNRS-OCA), A. Williams (PO-UWA), R. Martin (PO-UWA) report: We imaged the field of GRB 130313A detected by SWIFT (trigger 550906) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia. The observations started 52.3s after the GRB trigger (34.2s after the notice). The elevation of the field increased from 19 degrees above horizon and weather conditions were good. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect any optical transcient with a limiting magnitude of: t0+52.3s to t0+112.3s : R > 17.2 The second image is 30.0s exposure in tracking mode: t0+130s to t0+160s : R > 18.6 We co-added a series of exposures: t0+131s to t0+320.0s : R > 19.3 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. This message may be cited.