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 16661

GRB 140801A: Swift-XRT observations
2014-08-02T14:20:53Z (10 years ago)
Alessandro Maselli at INAF/IASF Palermo <>
A. Maselli and M. De Pasquale (INAF-IASFPA) report on behalf of the 
Swift-XRT team:

We have analysed 2.0 ks of XRT data for the FERMI/GBM detected burst GRB 
140801A (Pelassa, GCN Circ. 16658), from 36.4 ks to 48.0 ks after the 
GBM trigger. The data are entirely in Photon Counting (PC) mode. An 
X-ray source is found at the position of the optical transient detected 
by MASTER (Gorbovskoy et al.,  GCN Circ. 16653). Using 1893 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 = 44.06877, +30.93799 which is equivalent to:

RA (J2000): 02h 56m 16.50s
Dec(J2000): +30d 56' 16.8"

with an uncertainty of 2.5 arcsec (radius, 90% confidence). This 
position is 0.8 arcsec from the MASTER position. We believe that this 
source, which has a mean count rate of 2.3e-02 ct/sec, is the X-ray 
afterglow of GRB 140801A but further observations are needed to 
determine a decaying behaviour.

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