TITLE: GCN CIRCULAR NUMBER: 8996 SUBJECT: GRB 090313: Zadko Telescope observations DATE: 09/03/14 09:04:51 GMT FROM: David Coward at U of Western Aus. SUBJECT: GRB 090313: Zadko Telescope observations FROM: D.M Coward at UWA T. Vaalsta and D.M. Coward report on behalf of the Zadko Telescope Team. T. Vaalsta, D. Coward, J. Zadko, A. Imerito, D. Blair, R. Burman, P. Luckas, S. Gordon, K. Frost, A. Fletcher, J. Moore (University of Western Australia) M. Todd, M. Zadnik (Curtin University) M. Boer, A. Klotz (TAROT) The Zadko telescope started observing the field of GRB 090313 (trigger=346386, Mao et al. GCN 8980) 4.26h after the Swift trigger, under difficult conditions due to significant sky brightness from the Moon. Preliminary photometry of unfiltered images taken with an iKon DW436BV camera show a slow decay of the optical afterglow: Time(s) Magnitude ------------------------------------- 21356 18.02 +/- 0.08 22662 18.49 +/- 0.10 24115 18.49 +/- 0.10 26028 18.62 +/- 0.09 27890 18.78 +/- 0.09 29834 18.84 +/- 0.12 Magnitudes were calibrated with respect to the nearby USNOB1 star 0980-0264084 (13 13 36.392 +08 04 47.69). The optical afterglow is close to a 16.37 magnitude galaxy (PGC 1338801). The Zadko Telescope is currently being commissioned. This message is quotable in publications Dr David Coward Senior Research Fellow School of Physics University of Western Australia Crawley WA 6009 Tel: +61 8 6488 4563 Mobile 0423981240 Fax: +61 8 6488 1170