GCN Circular 3314

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.