TITLE:   GCN CIRCULAR
NUMBER:  22646
SUBJECT: GRB 180418A: Swift detection of a short burst
DATE:    18/04/18 06:55:40 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), P. A. Evans (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (PSU),
M. Stamatikos (OSU/NASA/GSFC) and A. Tohuvavohu (PSU) report on behalf
of the Neil Gehrels Swift Observatory Team:

At 06:44:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180418A (trigger=826428).  Swift could not immediately slew
to the burst due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 170.112, +24.956 which is 
   RA(J2000) = 11h 20m 27s
   Dec(J2000) = +24d 57' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
structure with a duration of about 1.5 sec.  The peak count rate
was ~8000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until T0+49.6
minutes. There will be no XRT or UVOT data until this time. 

Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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/too.html.)