TITLE: GCN CIRCULAR NUMBER: 16763 SUBJECT: GRB 140903A: Swift detection of a possible burst DATE: 14/09/03 15:56:04 GMT FROM: David Palmer at LANL J. R. Cummings (NASA/UMBC), D. N. Burrows (PSU), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 15:00:30 UT, BAT triggered on a possible GRB at RA, dec = 238.036, +27.578 (J2000). However, due to a TDRSS telemetry gap, no further data is available at this time. No XRT source was detected in 90 s of downlinked data taken approximately 1.5ks after the trigger time. We are waiting for the full dataset to detect and localise the XRT counterpart. No UVOT data is available at this time. The full data set will be available following the next ground pass. Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)