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GCN Circular 29018

GRB 201208A: Swift-XRT afterglow detection
2020-12-09T19:48:17Z (3 years ago)
Aaron Tohuvavohu at U Toronto <>
A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A.
Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and P.A. Evans (U.
Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 201208A (Dirirsa et al. GCN Circ. 29003),
collecting 5.0 ks of Photon Counting (PC) mode data between T0+70.4 ks
and T0+111.4 ks. 

Four uncatalogued X-ray sources are detected, of which one ("Source 2")
is above the 2SXPS 3-sigma upper limit at this position, and is
therefore likely the GRB afterglow. Using 2046 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 = 158.32352, -28.71989 which is equivalent to:

RA (J2000): 10h 33m 17.64s
Dec(J2000): -28d 43' 11.6"

with an uncertainty of 3.1 arcsec (radius, 90% confidence). This
position is 112 arcsec from the Fermi/LAT position.  The results of the
XRT-team automatic analysis of the likely afterglow are at
The results of the full analysis of the XRT observations are available

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