TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5594 SUBJECT: GRB060923C : Faulkes Telescope South optical limits DATE: 06/09/23 16:08:08 GMT FROM: Andrea Melandri at Liverpool John Moores U A. Melandri (Liverpool JMU), C. Guidorzi (Univ Bicocca & INAF-OAB), A. Gomboc (University of Ljubljana), I.A. Steele, R.J. Smith, C.G. Mundell, A. Monfardini, D. Carter, S. Kobayashi, D. Bersier, M. Bode (Liverpool JMU), P. O'Brien, E. Rol, N. Bannister (Leicester) report: The 2m Faulkes Telescope South (Siding Spring, Australia) automatically reacted to the Swift burst GRB 060923C (trigger 230711, Stamatikos et al., GCN 5591). Observations were performed in the R-band. From t=19.38 min to t=20.27 min (after the burst event) a 3x10s stacked image gives a limiting magnitude R > 19.5 inside the XRT error circle (Stamatikos et al. GCN 5591). This message can be cited.