TITLE: GCN CIRCULAR NUMBER: 21465 SUBJECT: GRB 170728A: 15 GHz upper limits from AMI DATE: 17/08/11 18:11:16 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) The AMI Large Array robotically triggered on the Swift alert for GRB 170728A (Cannizzo et al., GCN 21367) as part of the 4pisky program, and subsequent follow up observations were obtained up to 10 days post-burst. Our observations at 15 GHz on 2017 Jul 28.32, Jul 30.25, Aug 01.27 and Aug 05.23 (UT) do not reveal any radio source at the XRT location (Goad et al., GCN 21368), with 3sigma upper limits of 141 uJy, 131 uJy, 129 uJy and 133 uJy respectively. We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.