GCN Circular 5409

M. De Pasquale (UCL-MSSL), S. D. Barthelmy (GSFC),
S. Campana (INAF-OAB), J. R. Cummings (NASA/UMD),
O. Godet (U Leicester), C. Guidorzi (Univ Bicocca&INAF-OAB),
J. E. Hill (GSFC/USRA), S. T. Holland (GSFC/USRA),
J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA),
F. E. Marshall (NASA/GSFC), K. M. McLean (LANL/UTD),
K. L. Page (U Leicester), D. M. Palmer (LANL), S. B. Pandey (UCL-MSSL),
A. M. Parsons (GSFC), T. Sakamoto (NASA/ORAU) and
D. E. Vanden Berk (PSU) report on behalf of the Swift Team:

At 14:41:35 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060807 (trigger=223217).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA,Dec 252.527, +31.590
{16h 50m 07s, +31d 35' 25"} (J2000) with an uncertainty of 3 arcmin
(radius, 90% containment, including systematic uncertainty). 
The BAT light curve shows 1, possibly 2, peaks  with a duration
of about 15 sec.  The peak count rate was ~1000 counts/sec (15-350 keV),
at ~1 sec after the trigger. 

The XRT began taking data at 14:43:21 UT, 106 seconds after the BAT
trigger. The XRT on-board centroid algorithm did not find a source in
the image, however analysis of downlinked data finds an uncatalogued,
variable point source at the following location:  
RA(J2000): 16h 50m 02.77s, Dec(J2000) 31d 35m 31.1s with an estimated  
uncertainty of 4.2 arcseconds radius (90% containment). 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 110 seconds after the BAT trigger. No
afterglow candidate has been found in the initial data products. The
2.7'x2.7' sub-image covers 100% of the XRT error circle. The
3-sigma upper limit is about 19.7 mag. The 8'x8' region for the
list of sources generated on-board covers 100% of the XRT error
circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to
E(B-V) of  0.03. 

The Malindi telemetry downlink gap has just started, so we will not get
the full data set until ~22:30 UT. 

[GCN OPS NOTE(07aug06): Per author's request, the affilation of S.B.Pandey
was changed.]