[vsnet-grb-info 2501] GRB 051211B: Swift XRT confirmation of the afterglow

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4338
SUBJECT: GRB 051211B: Swift XRT confirmation of the afterglow
DATE:    05/12/12 13:51:50 GMT
FROM:    David Burrows at PSU/Swift  <dxb15 at psu.edu>

V. La Parola, V. Mangano (INAF-IASF), C. Pagani (INAF-OAB), and D. N. 
Burrows (PSU),  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).   With five orbits of data (from 11 ks to 36 ks after the burst), 
the uncataloged X-ray source reported in Pagani et al. (GCN 4332) is 
clearly fading, consistent with being the afterglow of this burst.  Our 
updated position is

RA 23:2:41.76, Dec 55:04:51.9 (345.6740, 55.0811),

which is 29".8  from the INTEGRAL position and 62".9 from the position of 
the candidate optical afterglow reported in GCN 4328 (Klotz et al.).  The 
lightcurve is initially flat, with a steep power law decay commencing about 
20 ks after the burst.  Observations are continuing.  Refined analysis, 
including decay indices and spectral results, will be issued in a further 
circular after accumulation of several more orbits of data.