[vsnet-grb-info 5440] Swift XRT follow-up observations of GRB071008

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7113
SUBJECT: Swift XRT follow-up observations of GRB071008
DATE:    07/11/19 14:50:58 GMT
FROM:    Alberto Moretti at Obs Brera Merate  <alberto.moretti at brera.inaf.it>

A. Moretti (INAF-OAB), C. Guidorzi (Univ. Bicocca & INAF-OAB), report
P. Romano (Univ. Bicocca & INAF-OAB) on behalf of the Swift XRT team:

The Swift XRT re-observed the field of GRB 071008 (trigger=293587,
Moretti et al., GCN Circ. 6856) on 2007 November 15-19 for a total
exposure of 10.7 ks.

The first source listed in GCN Circ 6866 (Moretti et al., 2007), which
is the only one in the refined BAT error circle (GCN Circ. 6869
Fenimore et al. 2007) is no more detectable. The chance probability of
no variation between the two epochs is < 1E-4. We conclude that this
source is the X-ray afterglow of GRB 071008 and its position is
RA(2000)=151.58851, Dec(2000)=44.3207 which corresponds to

RA(2000) = 10h06m21.24s
Dec(2000) = +44 19 14.6

with a 5.8" radius error circle (90% confidence).

The 3-sigma upper count rate limit at the position of the burst at
3.1E6 seconds after the trigger is 7e-4 counts/s which converts roughly
to 4e-14 ergs/s/cm2.

This circular is an official product of the Swift team