TITLE:   GCN CIRCULAR
NUMBER:  16467
SUBJECT: GRB 140628A: Swift detection of a burst
DATE:    14/06/28 14:01:58 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

E. Sonbas (NASA/GSFC/Adiyaman Univ.), M. G. Bernardini (INAF-OAB),
P. D'Avanzo (INAF-OAB), H. A. Krimm (CRESST/GSFC/USRA),
N. P. M. Kuin (UCL-MSSL), A. Y. Lien (NASA/GSFC/ORAU),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 13:35:37 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140628A (trigger=602803).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 40.661, -0.366 which is 
   RA(J2000) = 02h 42m 39s
   Dec(J2000) = -00d 21' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 10 sec.  The peak count rate
was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field after coming out of SAA mode at 
13:39:40.3 UT, 243 seconds after the BAT trigger. No source was 
detected in 20 s of promptly downlinked data. We are waiting 
for the full dataset to detect and localize the XRT counterpart. 

UVOT took a finding chart exposure of  48 seconds with the White filter
starting 278 seconds after the BAT trigger. No credible afterglow candidate has
been found in a partial 2.7'x2.7' sub-image. Results from the list of sources
generated on-board are not available at this time. 

Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 
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.)