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
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
Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.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.)