P.A. Evans (U. Leicester), P. Schady and M. de Pasquale (MSSL-UCL)
report on behalf of the Swift team:
Swift began observing the field of GRB 080702B (Cummings et al. GCN circ
7924) at 2008 July 02 at 17:38 UT, 17.3 hours after the burst. In 4 ks
of XRT data we do not detect any sources within the refined error circle
presented in GCN Circ 7924, down to a 3-sigma upper limit of 2.2 x 10-3
There are two sources within the original error circle in GCN Circ 7924.
The brightest lies at RA, Dec=355.6326, -5.5318 degrees, with an
estimated uncertainty of 4.7" (radius, 90% confidence). This is
coincident with a known optical source, and is not fading; this is
thus not the GRB afterglow.
The second object lies at RA,Dec=355.5665, -5.51410, which is equivalent
RA (J2000) = 23 42 15.95
Dec (J2000) = -05 30 50.8
with an estimated uncertainty of 6.3" (radius, 90% containment). The
source count rate is around 3e-3 counts per second, and we are unable
to determine at present whether this source is fading.
In 3.7 ks of UVOT data obtained using the White filter, no new sources are
detected. The 3-sigma upper limit at the position of the second XRT source
is 22.4 mag.
This circular is an official product of the Swift team.