TITLE: GCN CIRCULAR NUMBER: 12392 SUBJECT: Swift-BAT trigger 503926 is noise DATE: 11/09/24 16:05:45 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), D. Burrows (PSU), J. R. Cummings (GSFC/UMBC), E. A. Hoversten (PSU), H. A. Krimm (GSFC/USRA), S. Oates (UCL-MSSL), C Pagani (UL) (for the Swift team): Using the BAT data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of Swift-BAT trigger #503926 (Hoversten, et al., GCN Circ. 12391). This trigger is due to chance coincidence of noise fluctuations in the rate and image domains. XRT observations in Photon Counting mode data started 126 s after the  BAT trigger. In 2ks of PC data no source is detected inside the BAT error circle.  The three sigma upper limit is 4e-3 counts/second. This trigger is a noise event, and is not anything astrophysical.