GCN Circular 14946
V. D'Elia (ASDC), A. Y. Lien (NASA/GSFC/ORAU), D. Malesani (DARK/NBI), S. R. Oates (UCL-MSSL), K. L. Page (U Leicester) and P. Romano (INAF-IASFPA) report on behalf of the Swift Team: At 07:26:21 UT, the Swift Burst Alert Telescope (BAT) triggered (559221) on a noise fluctuation in the image domain which we likely believe was a chance coincidence with the source IGR J17544-2619 in the on-board catalog. As is typical for image triggers (64 sec, image significance=6.02 sigma), the real-time TDRSS lightcurve does not show anything significant. The XRT began observing the field at 07:28:32.9 UT, 131.7 seconds after the BAT trigger. XRT initially centroided on the IGR source IGR J17544-2619, however this is 378 arcseconds from the BAT position, well outside the BAT error circle. No source was found in the BAT error circle in 480 s of promptly-downlinked event data. UVOT took a finding chart exposure of 250 seconds with the U filter starting 137 seconds after the BAT trigger. No credible new source has been found in the initial data products. The overlap of the 8'x8' region for the list of sources generated on-board and the BAT error circle is 100%. No correction has been made for the large, but uncertain extinction expected.