TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3279 SUBJECT: Swift-BAT detection of GRB 050416b DATE: 05/04/16 23:23:57 GMT FROM: Scott Barthelmy at NASA/GSFC D. Hullinger (UMD), L. Barbier, S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), 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 22:35:54.11 UT Swift-BAT triggered on burst GRB 050416b (trigger=114797). The BAT flight position is RA,Dec=133.853,+11.173 (J2000). We note this is 17 deg from the Moon, hence the s/c did not slew because of the Moon observing constraint. The burst was 53 deg off the BAT bore sight. The lightcurve shows a narrow peak with a total burst duration of ~5 sec (T90=~3sec in 15-350 keV).