TITLE: GCN CIRCULAR NUMBER: 19339 SUBJECT: GRB 160424A - XRT position uncertain DATE: 16/04/25 07:49:42 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: During the XRT observations of GRB 160424A (Evans et al., GCN Circ. 19336) the star trackers onboard Swift were unable to acquire a correct lock. As a result of this the attitude solution for the spacecraft is uncertain, and visual inspection of the images shows that the position of the XRT afterglow is highly uncertain. Our best estimate of the position is as given in GCN Circ. 19336, however the uncertainty is ~50 arc sec. This circular is an official product of the Swift-XRT team.