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GCN Circular 15269

GRB 130929A: Swift detection of a burst
2013-09-29T10:07:59Z (11 years ago)
Jamie A. Kennea at PSU/Swift-XRT <>
F. E. Marshall (NASA/GSFC), J. R. Cummings (NASA/UMBC),
J. A. Kennea (PSU), C. Pagani (U Leicester), K. L. Page (U Leicester),
M. H. Siegel (PSU) and T. N. Ukwatta (MSU) report on behalf of the
Swift Team:

At 09:36:33 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130929A (trigger=572308).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 135.069, -47.565 which is 
   RA(J2000) = 09h 00m 17s
   Dec(J2000) = -47d 33' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
structure with a duration of about 10 sec.  The peak count rate
was ~3407 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 09:38:14.6 UT, 101.5 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 135.0241, -47.5605
which is equivalent to:
   RA(J2000)  = 09h 00m 05.78s
   Dec(J2000) = -47d 33' 37.9"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 110 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 

A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density. 

UVOT took a finding chart exposure of 150 seconds with the White 
filter  starting 280 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 0% of the  XRT error circle. The 8'x8'
region for the  list of sources  generated on-board covers 100% of the
XRT error  circle. The list of sources is  typically complete to about
18 mag. No  correction has been made for the large,  but uncertain
extinction  expected. 

Burst Advocate for this burst is F. E. Marshall (marshall AT 
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:
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