GCN Circular 17099
G. E. Anderson, R. P. Fender, T. D. Staley (University of Oxford), A. J. van der Horst (University of Amsterdam), A. Rowlinson (CASS) We observed the position of GRB 141121A (Lien et al., GCN 17075) at 15 GHz with the Arcminute Microkelvin Imager (AMI-LA) starting on 2014 Nov 24.17 to 24.33 UT, corresponding to 3 days post-burst. We have detected a radio source coincident with the optical counterpart (Tanga et al., GCN 17078) with a preliminary flux of 0.46 +/- 0.05 mJy. Earlier observations were conducted on 2014 Nov 21.16 to 21.25 UT and Nov 22.05 to 22.21 UT, corresponding to <6 minutes and 0.9 days post-burst, yielding a 3 sigma flux upper limit of 0.26 mJy and a marginal detection of 0.18 +/- 0.06 mJy, respectively. Further AMI monitoring is planned. We thank the AMI staff for scheduling these observations.