TITLE: GCN CIRCULAR NUMBER: 21023 SUBJECT: GRB 170419A: Zadko observatory - Gingin optical observations DATE: 17/04/20 14:00:15 GMT FROM: Alain Klotz at IRAP-CNRS-OMP A. Klotz, D. Turpin (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA), M. Boer, (UNS-CNRS-OCA), Gendre B. (UVI - Etelman Obs.), A. Williams (PO-UWA), R. Martin (PO-UWA) report: We imaged the field of GRB 170419A detected by SWIFT (trigger 748898) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia. The observations started 22.3h after the GRB trigger. The elevation of the field decreased from 49 degrees above horizon and weather conditions were good. We co-added a series of exposures but we did not find any optical transcient in the XRT error box provided by Goad et al. (GCNC 21015): t0+22.3h to t0+22.9h : Rlim = 21.0 Magnitudes were estimated with the nearby NOMAD1 stars and are not corrected for galactic dust extinction.