[vsnet-grb-info 2976] GRB 060223: Swift detection of a burst

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4813
SUBJECT: GRB 060223: Swift detection of a burst
DATE:    06/02/23 06:29:33 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc at milkyway.gsfc.nasa.gov>

J. R. Cummings (NASA/ORAU), S. D. Barthelmy (NASA/GSFC), P. T. Boyd
(NASA/GSFC), D. N. Burrows (PSU), M. Capalbi (ASDC), M. M. Chester
(PSU), J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt
(GSFC/UMD), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. 
Perri (ASDC) report on behalf of the Swift Team:

At 06:04:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060223 (trigger=192059).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA,Dec 55.216, -17.139 {03h 40m 52s, -17d 08' 19"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 15 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began taking data at 06:05:49 UT, 86 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. 

In response to the Swift/BAT trigger 192059, UVOT took a finding chart
exposure of nominally 200 seconds with the V filter starting 86.5
seconds after the BAT trigger. There is a candidate afterglow in the
sub-imagae and the list of sources generated on-board at (RA,DEC)
(J2000) of (55.2065, -17.1301) with a 1-sigma error radius of about 1
arcsec. This position is 45.9 arcsec from the center of the BAT error
circle. The estimated V magnitude is 17.6 with a 1-sigma error of
about 0.5 mag.