[vsnet-grb-info 2880] GRB 060209(?): Swift-BAT detection of a possible burst

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4717
SUBJECT: GRB 060209(?): Swift-BAT detection of a possible burst
DATE:    06/02/09 19:44:31 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <Scott at lheamail.gsfc.nasa.gov>

J. Osborne (U Leicester), S. Barthelmy (GSFC), N. Gehrels (GSFC),
J. Kennea (PSU), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
F. Marshall (GSFC), K. Page (U Leicester), D. Palmer (LANL),
T. Sakamoto (GSFC/ORAU), P. Schady (PSU/UCL-MSSL)
on behalf of the Swift team:

At 19:08:55 UT, Swift-BAT triggered and located GRB 060209 (trigger=180931).
The spacecraft slewed immediately.  The BAT on-board calculated location is
RA,Dec 65.454,+58.730d {04h 21m 49s,+58d 43' 47"} (J2000), with an uncertainty
of 3 arcmin (radius, 90% containment, stat+sys).  The TDRSS lightcurve
does not show anything significant (in T-20 to T+128 sec) which is consistant
with a weak short burst and with a cosmic ray shower.  We will not be able
to distinguish these until we get the full data in about an hour.

The XRT began taking data at 19:10:00 UT, 64 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 200 seconds with the V filter
starting 65 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 the expected extinction of about 2.9 magnitudes.