GCN Circular 16727
B.P Gompertz and K.L. Page (U. Leicester) report on behalf of the Swift-XRT team: We report on Swift-XRT observations of the field of the optical transient observed by MASTER II (Lipunov et al. GCN Circ 16720) in the error circle of the Fermi GBM discovered possible GRB (trigger number 430148973), 38.9 ks after trigger. In 5 ks of observations, no source is detected consistent with the MASTER position to a 3-sigma upper limit of 1.7E-3 cts/s. This circular is an official product of the Swift-XRT team.