TITLE: GCN CIRCULAR NUMBER: 35282 SUBJECT: GRB 231205B: Zadko observatory - Gingin optical observations DATE: 23/12/06 07:38:19 GMT FROM: Bruce Gendre at UVI <bruce.gendre@gmail.com> B. Gendre, E. Moore, E. Van Dongen, F. Panther, D. Coward, J. A. Moore (OzGrav-UWA), A. Klotz (IRAP-CNRS-OMP), and P. Thierry (AGORA), report: We imaged the field of GRB 231205B detected by SWIFT (Evans et al., GCN 35269, trigger 1200812) with the Zadko robotic telescope (D=100cm) located at Gingin, Australia. The observations started 201.6s after the GRB trigger (126.1s after the notice). The elevation of the field decreased from 25 degrees above horizon and weather conditions were poor, with high altitude clouds. The date of trigger : t0 = 2023-12-05T16:43:59.500 The first image is a 10.0s exposure in tracking mode. At the position of the XRT afterglow (Osborne et al, GCN 35275), we do not detect any OT with a limiting magnitude of: t0+201.6s to t0+211.6s : R > 16.2 We co-added a series of exposures: t0+217.3s to t0+344.2s : R > 17.2 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon=162.4895 lat=-22.7655 and the galactic extinction in R band is 0.3 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/35282. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...