GCN Circular 43369

R. Brivio (INAF-OAB), A. Mei (INAF-OAB), K. L. Page (U Leicester),
T. M. Parsotan (GSFC), C. Salvaggio (INAF-OAB),
B. Sbarufatti (INAF-OAB) and M. H. Siegel (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:

The downlinked data showed no obvious light curve structure, and the lack of the scaled map at the time prevented full verification of the low image significance of the event in the BAT data.

The XRT began observing the field at 09:03:15.2 UT, 112.0 seconds after
the BAT trigger. No source was detected in 930 s of promptly downlinked
data.

UVOT took a finding chart exposure of 250 seconds with the U filter starting
172 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 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.111.