[vsnet-grb-info 3973] GRB 061109: Swift detection of a possible burst

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5790
SUBJECT: GRB 061109: Swift detection of a possible burst
DATE:    06/11/09 00:57:49 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

A. D. Falcone (PSU), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), M. M. Chester (PSU),
J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC),
J. A. Kennea (PSU), C. B. Markwardt (GSFC/UMD),
F. E. Marshall (NASA/GSFC), K. M. McLean (LANL/UTD), C. Pagani (PSU),
D. M. Palmer (LANL), G. Sato (GSFC/ISAS) and L. Vetere (PSU) report on
behalf of the Swift Team:

At 00:30:19 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a possible GRB 061109 (trigger=237821). Swift slewed
immediately to the location. The BAT on-board calculated location is
RA,Dec 311.747, +24.166 {+20h 46m 59s, +24d 09' 59"} (J2000) with an
uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). 

The XRT began taking data at 00:31:28 UT, 69 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. The prompt lightcurve
from XRT reveals no detectable emission. We are waiting for
down-linked data to detect and determine if an afterglow is present. 

The usual UVOT data products (finding charts and source lists)
will be available when the full data set is down and processed
at ~02:15 UT. 

Due to a problem in the telemetry stream that started part way through 
the sequence of messages that come down TDRSS for each trigger, we do
not have any BAT lightcurves, XRT images or any of the UVOT messages.