GCN Circular 4885

H. Z. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC), A. P. Beardmore (U
Leicester), A. J. Blustin (UCL-MSSL), D. N. Burrows (PSU), J. R. 
Cummings (NASA/ORAU), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), F. 
E. Marshall (NASA/GSFC), D. M. Palmer (LANL), E. Rol (U Leicester)
and T. Sakamoto (NASA/ORAU) report on behalf of the Swift Team:

At 00:55:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060319 (trigger=202035). Swift slewed immediately to the
burst. The BAT on-board calculated location is RA,Dec 176.370,
+59.990 {11h 45m 29s, +59d 59' 25"} (J2000) with an uncertainty of 3
arcmin (radius, 90% containment, including systematic uncertainty). 
The BAT light curve showed a single-peaked structure with a
duration of about 15 sec. The peak count rate was ~2000 counts/sec
(15-350 keV), at ~4 sec after the trigger. 

The XRT began taking data at 00:57:56 UT, 134 seconds after the BAT
trigger.  The XRT on-board centroid algorithm did not find a source in the
image and no prompt position is available.  We are waiting for down-linked
data to detect and determine a position for the source. 

UVOT took a finding chart exposure of 100 seconds with the WHITE
filter starting 140 seconds after the BAT trigger. No afterglow
candidate has been found in the initial data products. The 2.7'x2.7'
sub-image covers 25% of the BAT error circle. The typical 3-sigma
upper limit has been about 18th mag. The 8'x8' region for the list of
sources generated on-board covers 100% of the BAT error circle. The
list of sources is typically complete to about 18.0 mag. No
correction has been made for extinction.