TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4378
SUBJECT: Possible GRB 051221B: Swift XRT position  
DATE:    05/12/21 23:01:31 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page, J. Racusin, A.P. Beardmore, D.N. Burrows and N. Gehrels report
on behalf of the Swift-XRT team:

We have analysed the first orbit of XRT data for BAT trigger 173904 (GCN
4376, Boyd et al.) and find a fading, uncatalogued source located at

RA(J2000)  = 20h 49m 35.1s
Dec(J2000) = 53h 02m 12.2s

with an estimated uncertainty of 4.5 arcsec (90% containment). This 
includes the latest XRT boresight correction and is 62 arcsec from the 
on-board BAT position given in GCN 4376.

From the current data, it is still not possible to determine whether the 
source is a GRB or a hard X-ray transient.