TITLE: GCN CIRCULAR NUMBER: 6301 SUBJECT: Swift-BAT Trigger 276045 is a Cosmic Ray Shower event DATE: 07/04/18 15:30:42 GMT FROM: Ann M. Parsons at NASA/GSFC/Swift D. Palmer (LANL), L. Barbier (GSFC), S.D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) on behalf of the Swift-BAT team: The BAT trigger 276045 (C. Guidorzi et al, GCN Circ 6299) is not a GRB. It is due to a cosmic ray shower in the spacecraft. All 90 events recorded in the BAT detector array occurred within a single 100 microsecond timestamp interval.