TITLE: GCN CIRCULAR NUMBER: 33208 SUBJECT: GRB 230123A: Zadko observatory - Gingin optical observations DATE: 23/01/23 14:31:21 GMT FROM: Bruce Gendre at UVI B. Gendre (UWA/OzGrav), G. Stratta (INAF/Goethe University Frankfurt), E. Moore (UWA/OzGrav), F. Panther (UWA/OzGrav), D. Coward (UWA/OzGrav), J. A. Moore (OzGrav-UWA), A. Klotz (IRAP-CNRS-OMP), and P. Thierry (AGORA) report: We imaged the field of GRB 230123A detected by SWIFT (trigger 1150429, GCN 33206, Williams et al. 2023) with the Zadko robotic telescope (D=100cm) located at the Zadko observatory - Gingin, Australia. The observations started 2.56h after the GRB trigger (t0+9213.4s). The elevation of the field decreased from 51 degrees above horizon and weather conditions were good. We observed the field for one hour, and have not detected any afterglow down to magnitude 18.7 in individual images. On a stack of 6 images, we reached an upper limit of R = 19.0 with no detection of the afterglow. Further observations are planned. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon=286.2098 lat=-47.6419 and the galactic extinction in R band is 0.0 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited. ======================================================================