Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 15424

GRB 131031A: Swift-XRT observations
2013-11-01T06:36:03Z (11 years ago)
Kim Page at U.of Leicester <>
B.P. Gompertz and K.L. Page (U. Leicester)  report on behalf of the
Swift-XRT team:

We have analysed 3.7 ks of XRT data for the Swift/BAT-detected burst:
GRB 131031A,  from 39.7 ks to 52.0 ks after the  Swift/BAT trigger. The
data are entirely in Photon Counting (PC) mode.  An X-ray source is
detected within the Swift/BAT error circle. Using 1649 s of PC mode
data and 1 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 = 29.61022, -1.57882 which is equivalent to:

RA (J2000): 01h 58m 26.45s
Dec(J2000): -01d 34' 43.7"

with an uncertainty of 4.7 arcsec (radius, 90% confidence). This
position is 91 arcsec from the Swift/BAT position.  The source has a
mean count rate of 8.8e-03 ct/sec; we cannot determine at the present
time whether it is fading.

The results of the XRT-team automatic analysis are available at

This circular is an official product of the Swift-XRT team.
Looking for U.S. government information and services? Visit