TITLE:   GCN CIRCULAR
NUMBER:  31068
SUBJECT: GRB 211106A: Swift-XRT afterglow detection
DATE:    21/11/09 19:35:25 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), B. Sbarufatti
(PSU), D.N. Burrows (PSU), J. D. Gropp (PSU), A.P. Beardmore (U.
Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB) and
P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
Swift/BAT-GUANO-detected burst GRB 211106A (Ridnaia et al. GCN Circ.
31054). The observations now extend from T0+39.3 ks to T0+290.7 ks. 

Of the sources reported by D'Elia et al. (GCN Circ. 31051), "Source 2"
is fading with 2.5 sigma significance and thus is believed to be the
GRB afterglow. Using 2766 s of PC mode data and 2 UVOT images, we find
an enhanced XRT position (using the XRT-UVOT alignment and matching
UVOT field sources to the USNO-B1 catalogue): RA, Dec = 343.58521,
-53.23028 which is equivalent to:

RA (J2000): 22h 54m 20.45s
Dec(J2000): -53d 13' 49.0"

with an uncertainty of 3.4 arcsec (radius, 90% confidence). This
position is 2.1 arcmin from the Swift/BAT-GUANO position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.7 (+0.5, -0.4).

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021466.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021466.

This circular is an official product of the Swift-XRT team.