GCN Circular 20283

A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC),
H. A. Krimm (CRESST/NSF/USRA), D. M. Palmer (LANL) and
M. H. Siegel (PSU) report on behalf of the Swift Team:

At 03:47:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 161218A (trigger=727288).  Swift could not slew to the burst
do to an observing constraint.  The BAT on-board calculated location is 
RA, Dec 245.257, -4.114 which is 
   RA(J2000) = 16h 21m 02s
   Dec(J2000) = -04d 06' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single complex
structure with a duration of about 10 sec.  The peak count rate
was ~20000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 15:54 UT on 2017 January 08. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.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/too.html.)