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GCN Circular 16546

Subject
GRB 140709A: Swift detection of a burst
Date
2014-07-09T01:28:06Z (10 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
L. M. Z. Hagen (PSU), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC),
M. M. Chester (PSU), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU)
and M. H. Siegel (PSU) report on behalf of the Swift Team:

At 01:13:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140709A (trigger=603810).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 304.639, +51.223 which is 
   RA(J2000) = 20h 18m 33s
   Dec(J2000) = +51d 13' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several peaks
with a total duration of about 80 sec.  The peak count rate
was ~2800 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 01:15:04.0 UT, 82.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 304.66332, 51.22316 which
is equivalent to:
   RA(J2000)  = 20h 18m 39.20s
   Dec(J2000) = +51d 13' 23.4"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 54 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

The initial flux in the 2.5 s image was 1.01e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 92 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 100% of  the XRT error circle. The typical
3-sigma upper limit has been about 19.6 mag. Results from the list of
sources generated on-board are not available at this  time. No
correction has been made for the expected extinction corresponding to
E(B-V) of 0.40. 

Burst Advocate for this burst is L. M. Z. Hagen (lea.zernow.hagen AT gmail.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.)
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