TITLE:   GCN CIRCULAR
NUMBER:  30329
SUBJECT: GRB 210626A: Swift-XRT afterglow detection
DATE:    21/06/27 00:08:12 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), A. D'Ai
(INAF-IASFPA), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea
(PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-GUANO-detected burst GRB 210626A (Aaron Tohuvavohu et al. GCN
Circ. 30325), collecting 1.4 ks of Photon Counting (PC) mode data
between T0+29.7 ks and T0+31.1 ks. 

An uncatalogued X-ray source is detected and is above the 2SXPS 3-sigma
upper limit at this position, and is therefore likely the GRB
afterglow. Using 1180 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 = 221.52429, -1.15625
which is equivalent to:

RA (J2000): 14h 46m 05.83s
Dec(J2000): -01d 09' 22.5"

with an uncertainty of 5.7 arcsec (radius, 90% confidence). This
position is 5.7 arcmin from the Swift/BAT-GUANO position.  We cannot
determine at the present time whether the source is fading.

The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/ToO_GRBs/00021453/Source1.php.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021453.

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