GCN Circular 14703

B.P. Gompertz (U Leicester), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),
A. Y. Lien (NASA/GSFC/ORAU), F. E. Marshall (NASA/GSFC),
C. J. Mountford (U Leicester), C. Pagani (U Leicester),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 14:21:30 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130527A (trigger=556753).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 309.279, -24.728 which is 
   RA(J2000) = 20h 37m 07s
   Dec(J2000) = -24d 43' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex peak
structure with a duration of at least 20 sec.  The peak count rate
was ~25000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 14:23:15.4 UT, 105.2 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 309.2749, -24.7244 which is equivalent to:
   RA(J2000)  = +20h 37m 5.98s
   Dec(J2000) = -24d 43' 27.8"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 18 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 2.88e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 113 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
0.04. 

Burst Advocate for this burst is B.P. Gompertz (bpg6 AT le.ac.uk). 
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.)