[vsnet-grb-info 22777] Swift Trigger 911102: a possible GRB

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24876
SUBJECT: Swift Trigger 911102: a possible GRB
DATE:    19/06/24 21:03:50 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien at nasa.gov>

S. B. Cenko (GSFC), J.D. Gropp (PSU), N. J. Klingler (PSU),
A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), D. M. Palmer (LANL),
T. Sakamoto (AGU) and A. Tohuvavohu (PSU) report on behalf of the Neil
Gehrels Swift Observatory Team:

At 20:40:40 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a possible GRB (trigger=911102). Swift did not slew
immediately due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 144.524, +46.476 which is 
   RA(J2000) = 09h 38m 06s
   Dec(J2000) = +46d 28' 34"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual with an image trigger, 
the available BAT light curve shows no significant structure. 

Due to an observing constraint, Swift will not slew until T0+51
minutes. There will be no XRT or UVOT data until this time. 

Due to the marginal significance of this image trigger (7.2 sigma in
on-board imaging, with a reduced significance in ground processing)
and the lack of immediate XRT follow-up, we cannot yet confirm
that this is an astrophysical event. 

The determination of the reality of this event will require
the full downlinked dataset or the detection of the source
in the XRT follow-up after it comes out of observing constraint. 

Burst Advocate for this burst is S. B. Cenko (brad.cenko AT 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/)