GCN Circular 19645

S. B. Cenko (GSFC), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC),
L. Izzo (IAA-CSIC), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB/PSU) and T. N. Ukwatta (LANL) report on behalf
of the Swift Team:

At 12:10:05 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160703A (trigger=702699).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 287.392, +36.901 which is 
   RA(J2000) = 19h 09m 34s
   Dec(J2000) = +36d 54' 04"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 60 sec.  The peak count rate
was ~10000 counts/sec (15-350 keV), at ~22 sec after the trigger. 

XRT is temporarily offline, and so there will be no immediate data
from this GRB. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 75 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.14. 

Burst Advocate for this burst is S. B. Cenko (brad.cenko 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.)