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GCN Circular 34829

GRB 231017A: Swift-XRT observations
2023-10-18T15:56:18Z (8 months ago)
Phil Evans at U of Leicester <>
S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L.
Page (U. Leicester), A.P. Beardmore (U. Leicester), E. Ambrosi 
A. Tohuvavohu (U. Toronto) and P.A. Evans (U. Leicester) reports on
behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-GUANO-detected burst GRB 231017A (GCN Circ. 34824, DeLaunay
et al.), collecting 4.2 ks of Photon Counting (PC) mode data between
T0+32.7 ks and T0+101.7 ks. 

One uncatalogued X-ray source has been detected consistent with being
within 493 arcsec of the Swift/BAT-GUANO position, it is below the RASS
limit and shows no definitive signs of fading. Therefore, at the
present time we cannot confirm this as the afterglow. Details of this
source are given below:

Source 2:
  RA (J2000.0):  86.1666  =  05:44:39.99
  Dec (J2000.0): +56.7487  =  +56:44:55.3
  Error: 8.4 arcsec (radius, 90% conf.)
  Count-rate: (2.09 [+1.11, -0.84])e-3 ct s^-1	 
  Distance: 301 arcsec from Swift/BAT-GUANO position.
  Flux: (3.3 [+1.8, -1.3])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Two uncatalogued sources were also detected too far from the GRB
position to be likely afterglow candidates.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at

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

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