[vsnet-grb-info 5585] GRB 080130: further Swift XRT observations confirm fading source

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7247
SUBJECT: GRB 080130: further Swift XRT observations confirm fading source
DATE:    08/02/01 14:16:33 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1 at star.le.ac.uk>

R.L.C. Starling, P.A. Evans, P.T. O'Brien (U. Leicester), C. Guidorzi 
(U. Bicocca/INAF-OAB) and M. Stamatikos (GSFC/ORAU) report on behalf of 
the Swift XRT team:

Swift XRT re-observed the field of possible ground-detected GRB 080130 
(Copete et al., GCN 7242), approximately 34 hours after the burst. In 
4.98ks of Photon Counting (PC) mode data starting 2008-01-31:16:01 and 
ending 2008-01-31:20:51 we still detect an X-ray source inside the BATSS 
error circle at the 3-sigma level (Starling and Stamatikos, GCN 7243). By 
combining both XRT datasets for this field totalling ~7 ks we refine the 
source position to RA,Dec=261.61484,-53.18742 deg, equivalent to:

RA (J2000)= 17h 26m 27.56s
Dec(J2000)= -53d 11' 14.7"

with an uncertainty of 5 arsec (radius, 90% confidence). This is 6.2 
arcsec from the previously reported XRT position, and 2.2 arcmin from the 
BATSS position.

The count rate of the source in this second observation is 0.004+/-0.001
counts/s. Compared to the earlier measured count rate of 0.010+/-0.002
counts/s we can confirm that the source has faded. We conclude that GRB 
080130 was a real GRB, and that the source reported here is its X-ray 
afterglow.

This is an official product of the Swift XRT team.