TITLE:   GCN CIRCULAR
NUMBER:  8242
SUBJECT: GRB 080916B: Swift-XRT afterglow detection
DATE:    08/09/16 15:36:21 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>

G. Stratta, M. Perri, P. Evans report on behalf of
the Swift-XRT Team:

The XRT began observing the field at 15:07:22.2 UT, 1354.9 seconds
after the BAT trigger. Using promptly downlinked data we find an
uncatalogued X-ray source located at RA, Dec 163.66560, 69.06574 which
is equivalent to:
   RA(J2000)  = 10h 54m 39.74s
   Dec(J2000) = +69d 03' 56.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 94 arcseconds from the BAT onboard position, within the BAT
error circle.

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.8e+20 cm^-2 (Kalberla et al. 2005).