TITLE: GCN CIRCULAR NUMBER: 20205 SUBJECT: Swift Trigger 723539 is not an astrophysical event DATE: 16/11/23 13:53:47 GMT FROM: David Palmer at LANL K. L. Page (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 13:34:37 the Swift Burst Alert Telescope detected Cyg X-1 at its typical flux levels. BAT misidentified this detection as a new source and reported it as a trigger (trigger=723539). This is not an astrophysically interesting event.