TITLE:   GCN CIRCULAR
NUMBER:  4071
SUBJECT: GRB 051008: early Swift XRT analysis
DATE:    05/10/08 18:45:02 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>

M. Perri, M. Capalbi (ASDC), D.N. Burrows (PSU) report on behalf of the
Swift XRT team:

XRT began observing the field at 17:23:52 UT, about 50 minutes after the
BAT trigger. The on-board centroiding algorithm did not converge on a
source, so no prompt X-ray position is available.

However, the downlinked lightcurve shows evidence for a fading X-ray
source in the field of view. There are no catalogued X-ray sources in
the field, indicating that this source is the GRB afterglow.

Further analysis will require processing of the XRT full telemetry data
following the next ground station contact.