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GCN Circular 15284

GRB 131002B: Swift detection of a burst
2013-10-02T11:21:59Z (11 years ago)
Jamie A. Kennea at PSU/Swift-XRT <>
M. C. Stroh (PSU), D. N. Burrows (PSU), V. D'Elia (ASDC),
P. A. Evans (U Leicester), C. Gronwall (PSU), J. A. Kennea (PSU),
P. T. O'Brien (U Leicester), T. Sakamoto (AGU) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 10:54:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131002B (trigger=572742).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 75.061, -75.727 which is 
   RA(J2000) = 05h 00m 15s
   Dec(J2000) = -75d 43' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak 
with a duration of about 40 sec.  The peak count rate
was ~1800 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 10:55:21.3 UT, 52.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 75.1213, -75.7017 which is equivalent to:
   RA(J2000)  = +05h 00m 29.11s
   Dec(J2000) = -75d 42' 06.1"
with an uncertainty of 5.9 arcseconds (radius, 90% containment). This
location is 105 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 7.25e-10 erg cm^-2 s^-1 (0.2-10

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 62 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.  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 expected extinction corresponding to
E(B-V) of  0.12. 

Burst Advocate for this burst is M. C. Stroh (stroh 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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