TITLE:   GCN CIRCULAR
NUMBER:  19057
SUBJECT: GRB 160223A: Swift detection of a burst
DATE:    16/02/23 02:11:02 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

C. B. Markwardt (NASA/GSFC), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC) and D. M. Palmer (LANL) report on behalf of
the Swift Team:

At 01:44:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160223A (trigger=675361).  Swift could not slew
immediately to the burst due to a Moon observing constraint. 
The BAT on-board calculated location is 
RA, Dec 147.584, +9.373 which is 
   RA(J2000) = 09h 50m 20s
   Dec(J2000) = +09d 22' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure near T+0 s about 30 seconds long, followed by an
additional brighter structure peaking at around T+100 for
a total duration of ~120 seconds.  The peak count rate
was ~2200 counts/sec (15-350 keV), at ~110 sec after the trigger. 

Due to the proximity to the Moon this GRB will not be observable by 
XRT or UVOT until 22:27UT on Feb 23rd, 2016. 

Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt 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/too.html.)