[vsnet-grb-info 2495] GRB 051211B: Swift XRT Observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4332
SUBJECT: GRB 051211B: Swift XRT Observations
DATE:    05/12/12 04:46:11 GMT
FROM:    David Burrows at PSU/Swift  <dxb15 at psu.edu>

C. Pagani (INAF-OAB), D. N. Burrows (PSU), V. Mangano and V. La Parola 
(INAF-IASF) report on behalf of the Swift XRT team:

The Swift XRT began observing GRB 051211B, detected by INTEGRAL (Mereghetti 
et al., GCN 4327), at 01:05:28 UT on 12 December 2005 (10.8 ks after the 
burst).  In the first orbit of data (2.4 ks of exposure time), an 
uncataloged X-ray source was detected at the following position:
RA,Dec = 345.6762,+55.081 {23:02:42.3, +55:04:51.7} (J2000)
with an uncertainty of 4.5 arcsec radius (90% containment).  This position 
includes corrections for the XRT boresight.  We detected 58 photons from 
this source in Photon-Counting mode at a count rate of 0.024 cps, 
corresponding to an observed flux of about 1.3x10-12 ergs/cm^2/sec.

The X-ray source is 25 arcsec from the INTEGRAL position (GCN 4327) and 58 
arcsec from the candidate optical afterglow reported in GCN 4328.  There is 
no X-ray source visible at the position of the candidate optical afterglow.

With the data available at this time we cannot determine whether or not 
this source is fading.  Observations are continuing, and we will report 
further results in a later circular.