GCN Circular 42648

S. Campana (INAF-OAB), D.N. Burrows (PSU), S. Lanava (PSU), S. Dichiara
(PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.
Melandri (INAF-OAR), T. Sbarrato (INAF-OAB) and P.A. Evans (U.
Leicester) reports on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of GRB 251111A. We
searched for X-ray sources in  2.1 ks of Photon Counting (PC) mode
data. The total exposure at the position of the afterglow (see below)
is 2.1 ks, obtained between T0+7.6 ks and T0+36.9 ks.

An uncatalogued X-ray source is detected and is believed to be the
afterglow. Using 305 s of PC mode data and 1 UVOT image, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 32.36166, +5.22815
which is equivalent to:

RA (J2000): 02h 09m 26.80s
Dec(J2000): +05d 13' 41.3"

with an uncertainty of 5.1 arcsec (radius, 90% confidence). The
observed count rate was 2.5 (+1.2, -0.9)e-02 count/s at T0+7.7 ks,
falling to 5.2 (+2.6, -1.9)e-03 at T0+33.8 ks, which indicates the
X-ray source is fading.

The results of the XRT-team automatic analysis are available at
https://www.swift.ac.uk/xrt_products/03000189.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/SVOM/SVOM_FIELD00049.

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