GCN Circular 5221

M. J. Page (UCL-MSSL), A. J. Blustin (UCL-MSSL), P. J. Brown (PSU),
O. Godet (U Leicester), S. T. Holland (GSFC/USRA),
J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA), C. Pagani (PSU),
A. M. Parsons (GSFC), G. Sato (GSFC/JSPS/USRA) and
M. Stamatikos (NASA/ORAU) report on behalf of the Swift Team:

At 18:15:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060605 (trigger=213630).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA,Dec 322.144, -6.060 {21h 28m 35s, -06d 03' 36"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a FRED-like
structure with a duration of about 20 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began taking data at 18:17:17 UT, 93 seconds after the BAT
trigger. The XRT on-board centroid algorithm did not find a source in
the image, however analysis of downlinked PC mode data finds a faint,
uncatalogued point source at the following location: 
RA(J2000): 21h 28m 37.2s Dec(J2000): -06d 03m 35.3s, with an estimated 
error of 4 arcsec radius (90% containment). This position is 39 arcsec 
from the center of the BAT error circle and is 4.5 arcsec from the
UVOT candidate. 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 98 seconds after the BAT trigger. There
is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image
at (RA,DEC) (J2000) of (322.1555,-6.0587) or
(21h28m37.32s,-06o03'31.3")  with a 1-sigma error radius of about 0.5
arc sec. This position is 41.3 arc sec. from the centre of the BAT
error circle. The estimated magnitude is 17.4 with a 1-sigma error of
about 0.5 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of  0.05.