TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3314 SUBJECT: Swift Detection of GRB 050422 DATE: 05/04/22 09:26:09 GMT FROM: Louis M Barbier at NASA/GSFC/Swift L. Barbier (GSFC), D. Palmer (LANL), D. Burrows (PSU), A. Blustin (MSSL), H. Krimm (GSFC/USRA), N. Gehrels (GSFC), K. McGowan (MSSL), M. Chester (PSU) At 07:52:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050422 (trigger #115214). The BAT on-board calculated location is RA, dec 324.454, +55.799 (J2000) with an uncertainty of 4 arcmin (radius, 3-sigma, including estimated systematic uncertainty). The BAT light curve showed a multipeak structure with a duration of about 60 seconds. The peak count rate measured by BAT was about 1000 counts/sec in the 15 - 350 keV band, occurring 50 seconds after the trigger. The Swift spacecraft slewed at about T+60 seconds onto the BAT position. No BAT position message was received from TDRSS due to the fact that the burst occurred during a Malindi pass. The spacecraft executed a prompt slew and the XRT began taking data on the target at 07:54:29.4 UT. The XRT image looks like a cosmic ray hit, not a real source. Therefore the XRT position may be incorrect. However, the XRT spectra and lightcurve look like there is a real source in the field of view. Verification of the XRT position will require analysis of ground-processed data following the next ground station pass. The Swift Ultra Violet/Optical (UVOT) observations began at 07:54:32.2 UT, 112 seconds after the BAT trigger. The first data taken after the spacecraft settled was a 100 sec exposure using the V filter with the midpoint of the observation at 162 sec after the BAT trigger. This image was sent directly to the ground via TDRSS with the FOV pixel binning set at 8x8 pixels to reduce telemetry. A comparison against the Digitized Sky Survey reveals no new source inside the BAT error circles at RA, dec 324.454, 55.799 (J2000) with a radius of 4 arcmin.