TITLE:   GCN CIRCULAR
NUMBER:  41115
SUBJECT: Swift Trigger 1334535: a possible GRB 250718A
DATE:    25/07/18 00:47:35 GMT
FROM:    Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>

M. H. Siegel (PSU), R. Gupta (NASA GSFC), S. Lanava (PSU),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB) and M. A. Williams (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 00:14:02 UT, the Swift Burst Alert Telescope (BAT) triggered and
located possible GRB 250718A (trigger=1334535). 
The BAT on-board calculated location is 
RA, Dec 241.998, -11.993 which is 
   RA(J2000) = 16h 07m 59s
   Dec(J2000) = -11d 59' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a sharp rise with
a duration of just a few milliseconds.  The peak count rate was ~1070
counts/sec (15-350 keV), at ~0 sec after the trigger.

Due to an observing constraint, Swift will not slew to the burst until
01:07 UT. Due to the marginal significance of the BAT image (6.85
sigma), and the lack of prompt XRT and UVOT data, this trigger may be
due to a noise fluctuation. Further data are required to determine the
nature of this trigger.

Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu).
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/)