TITLE:   GCN CIRCULAR
NUMBER:  36626
SUBJECT: Swift Trigger 1235109: a possible GRB 240606A
DATE:    24/06/06 04:07:34 GMT
FROM:    Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>


A. D'Ai (INAF-IASFPA), R. Gupta (NASA/GSFC), A. Y. Lien (U Tampa) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 03:33:46 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a possible GRB 240606A (trigger=1235109). 
Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 12.125, -19.747 which is 
   RA(J2000) = 00h 48m 30s
   Dec(J2000) = -19d 44' 49"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve does not show any
obvious structure. 

The XRT began observing the field at 03:35:56.7 UT, 129.8 seconds after
the BAT trigger. No source was detected in 1.7 ks of promptly
downlinked data. We are waiting for the full dataset to detect and
localise the XRT counterpart. 

UVOT data are unavailable at this time. 

Due to the marginal significance of the BAT image (6.54 sigma), 
and the lack of an observed counterpart in the XRT data, 
this trigger may be due to a noise fluctuation. Further ground
data are required to determine the nature of this trigger. 

Burst Advocate for this burst is A. D'Ai (antonino.dai AT inaf.it). 
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/)