TITLE: GCN CIRCULAR NUMBER: 21950 SUBJECT: GRB 170903A: 15 GHz upper limits from AMI DATE: 17/10/01 20:12:06 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 170903A (Markwardt et al., GCN 21793) 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 Sep 03.57, Sep 04.79, Sep 06.82, Sep 12.66 (UT) do not reveal any radio source at the XRT location (Goad et al., GCN 21797), with 3sigma upper limits of 225 uJy, 120 uJy, 126 uJy, 99 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/.