[vsnet-grb-info 6683] Swift detection of a possible GRB (trigger 325707)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8285
SUBJECT: Swift detection of a possible GRB (trigger 325707)
DATE:    08/09/23 22:12:54 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

S. Immler (CRESST/GSFC/UMD), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU),
J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC),
C. Gronwall (PSU), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), V. La Parola (INAF-IASFPA),
V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
A. M. Parsons (GSFC), B. Sbarufatti (INAF-IASFPA),
M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester) and
M. C. Stroh (PSU) report on behalf of the Swift Team:

At 21:49:17 UT, the Swift Burst Alert Telescope (BAT) triggered and
produced a location for trigger=325707.  Swift slewed immediately to the location. 
The BAT on-board calculated location is 
RA, Dec 288.385, +25.832 which is 
   RA(J2000)  =  19h 13m 32s
   Dec(J2000) = +25d 49' 56"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multiple very weak peaks
with a duration of about 20-30 sec.  The peak count rate
was ~900 counts/sec (15-350 keV), at ~8 sec after the trigger. 

The XRT began observing the field at 21:50:37.4 UT, 80.1 seconds after
the BAT trigger. No source was detected in the promptly available XRT
data. We are waiting for the full dataset to detect and localise the
XRT counterpart, if any. 

There are no UVOT prompt images available. 

Given the marginal significance of the BAT detection,
and the lack of a source detection in the immediately
available XRT data, we cannot confirm that this is a GRB. 
This will be determined when the full dataset is downlinked
via Malindi. 

Burst Advocate for this burst is S. Immler (immler AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)