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GCN Circular 16978

GRB 141028A: Swift/XRT detection of the X-ray afterglow
2014-10-29T02:14:36Z (10 years ago)
Jamie A. Kennea at PSU/Swift-XRT <>
J. A. Kennea (PSU), J. L. Racusin (NASA/GSFC) and C. Pagani (UL) report on 
behalf of the Swift Team:

Swift-XRT has observed the error circle of the Fermi/LAT GRB 141028A in a 
series of observations tiled on the sky. The total exposure time is 2.0 ks 
spread over 7 fields; the maximum exposure within the sky observed was 766 
s. The observations started 31.0 ks after the Fermi/LAT trigger. Within 
these data we detect a bright, uncatalogued X-ray source at RA, Dec= 
322.60078, -0.23116 which is equivalent to:

RA (J2000.0)	= 21h 30m 24.19s
Dec (J2000.0) = -00d 13' 52.2"

with an uncertainty of 5.8 arcsec (radius, 90% confidence). The exposure 
at this location was 277 s. We note that this source is 4.8 arcsec from 
the position of the candidate MASTER afterglow position (GCN #16972) which 
has been confirmed to be fading by GROND (GCN #16977), and does not match 
any previously catalogued source. The source is significantly brighter 
than the RASS limit and therefore we suggest that this is the X-ray 
afterglow of GRB 141028A. More observations will be required to determine 
if the source is fading in X-rays.

The results of the automatic processing for this source are available at This 
circular is an official product of the Swift-XRT team.
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