TITLE:   GCN CIRCULAR
NUMBER:  3315
SUBJECT: GRB 050422: Swift XRT Position
DATE:    05/04/22 11:05:11 GMT
FROM:    David Burrows at PSU/Swift  <dxb15@psu.edu>

C. Pagani (INAF-OAB), D. N. Burrows (PSU), A. P. Beardmore (U. Leicester), 
and N. Gehrels (GSFC) report on behalf of the Swift XRT team:

The Swift BAT instrument detected a GRB at 07:52:40 UT on 22nd April 2005 
(GCN Circ 3314). The spacecraft executed a prompt slew and the XRT began 
taking data on the target at 07:54:29.4 UT.  Due to the presence of a 
cosmic ray in the initial image the on-board software could not properly 
centroid on the GRB, and the position generated on-board and sent out 
automatically through BACODINE was incorrect (the Notice indicated that 
this position was probably a cosmic ray).  From ground processed data we 
find a uncataloged, rapidly X-ray source within the BAT error circle, 
located at:

RA(J2000) = 21:37:54.5,
Dec(J2000) = +55:46:46.6.

We estimate an uncertainty of about 5 arcseconds radius (90% 
containment).  This position is 84 arcseconds from the BAT position 
reported in GCN 3314.