GCN Circular 11577

F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB), M. M. Chester (PSU),
V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
O. M. Littlejohns (U Leicester), C. B. Markwardt (NASA/GSFC),
M. Perri (ASDC), J. L. Racusin (NASA/GSFC), T. Sakamoto (NASA/UMBC),
C. J. Saxton (UCL-MSSL), M. H. Siegel (PSU),
E. Sonbas (GSFC/USRA/Adiyaman Univ.), G. Stratta (ASDC) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 17:31:52 UT, the Swift Burst Alert Telescope (BAT) triggered (=442771)
on a noise fluctuation while entering the SAA. 
Swift slewed immediately to the trigger location. 

The XRT began observing the field at 17:33:11.7 UT, 79.1 seconds after
the BAT trigger. No source was detected in 844 s of promptly downlinked
data. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 962 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 25% of
the BAT 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
BAT 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
0.01. 

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.)