TITLE: GCN CIRCULAR NUMBER: 3172 SUBJECT: Very questionable identity of Swift-BAT GRB050402 (Trig=113225) DATE: 05/04/02 15:45:36 GMT FROM: Scott Barthelmy at NASA/GSFC S. Barthelmy, L. Barbier (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD), 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 06:09:55 2-April-2005, UT Swift-BAT triggered on a marginal event (trigger=113225) which has been reported as GRB 050402 (GCNs 3167, 3168, 3169, 3170). The BAT team believes that the automated notice sent out earlier is likely consistent with a noise fluctuation, but we can not absolutely rule out that it was due to a very soft, weak GRB. The reasons which make this a questionable detection are: (a) detected only in the 15-25 keV band, (b) the image significance is very marginal, and (c) the noise in the detector array is slightly elevated during this interval (thus increasing the chance coincidence of a rate fluctuation and an image-domain fluctuation).