TITLE: GCN CIRCULAR NUMBER: 10127 SUBJECT: GRB 091102 : Faulkes Telescope South Upper Limits DATE: 09/11/03 12:07:11 GMT FROM: Zach Cano at ARI/John Moores Liverpool Z. Cano (Liverpool JMU), C. Guidorzi (U. Ferrara), A. Melandri, C.G. Mundell, D.Bersier, N.R. Clay, S. Kobayashi, C.J. Mottram, R.J. Smith, I.A. Steele (Liverpool JMU), A. Gomboc (U. Ljubljana)on behalf of a larger collaboration report: Following Swift detection of GRB 091102 (Hoversten et al. GCN Circ. 10117), Faulkes Telescope South (Australia) reacted automatically and began observing at 14:37:06 UT in BVRi. We detect no new source within the XRT error circle (Baumgartner et al., GCN 10121). In our first R-band image, which is contemporaneous with the images taken by A. de Ugarte Postigo et al. (GCN 10122), we do not detect their afterglow candidate. We have attached a finder chart of the GCN field (taken at T-To=186s): http://www.fe.infn.it/u/guidorzi/GRB091102/091102_FTS_DM.jpg We find the following upper limits, as calibrated against nearby USNO object 0174-0110239: T_exp T-T0(mid exposure) mag_limit ----------------------------------------- 30s 186 s R2 > 19.7 120s 2.07 hrs B2 > 18.7 120s 2.18 hrs I2 > 20.7 120s 2.12 hrs R2 > 20.2