Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 22308

GRB 180103A: Swift-XRT observations
2018-01-08T08:02:51Z (6 years ago)
Kim Page at U.of Leicester <>
A. Melandri (INAF-OAB), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A.
Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) 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-detected burst GRB 180103A (Beardmore et al. GCN Circ.
22305), collecting 2.0 ks of Photon Counting (PC) mode data between
T0+344.2 ks and T0+350.7 ks. 

One uncatalogued X-ray source has been detected consistent with being
within 296 arcsec of the Swift/BAT 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 1:
  RA (J2000.0):  159.6016  =  10:38:24.37
  Dec (J2000.0): -53.5560  =  -53:33:21.6
  Error: 3.8 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.0207 +/- 0.0054 ct s^-1   
  Distance: 35 arcsec from Swift/BAT position.
  Flux: (4.9 +/- 1.3)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

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.
Looking for U.S. government information and services? Visit