TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3288 SUBJECT: Swift-BAT detection of the bright and long GRB 050418 DATE: 05/04/18 11:49:31 GMT FROM: Takanori Sakamoto at NASA/GSFC L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), K. Hurley (UC Berkeley), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F. Marshall (GSFC), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama), J. Tueller (GSFC) on behalf of the Swift-BAT team: At 11:00:34.6 UT Swift-BAT triggered on burst GRB 050418 (trigger=114893). The BAT flight position is RA,Dec=44.341,-18.538 (J2000). We note this is 34 deg from the Sun, hence the s/c did not slew because of the Sun observing constraint. The burst was 39 deg off the BAT boresight. The lightcurve shows a main peak of duration 15-20 seconds, followed by apparent peaks at up to 70-80 seconds after the trigger. The peak count rate measured by BAT was 4500 counts/sec in the 15-350 keV band.