GCN Circular 15972

S. T. Holland (STScI) and J. L. Racusin (NASA/GSFC) report on behalf
of the Swift/UVOT team:

    The Swift/UVOT began settled observations of the field of GRB
140311B 3398 s after the BAT trigger (Racusin et al. 2014, GCNC
15945). We do not detect any new source consistent with the Nansan
afterglow position (Xu et al. 2014, GCNC 15949) in any of the UVOT
exposures. Preliminary 3-sigma upper limits, using the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373),
for the finding chart and summed exposures are presented below.

---------------------------------------------------
Filter        TSTART     TSTOP   Exposure       Mag
---------------------------------------------------
white (FC)      3398      3548        147     >21.2
---------------------------------------------------
v               3555      5191        393     >20.0
b               4375      5990        372     >20.4
u               4170      5806        393     >20.2
uvw1            3965      5601        393     >20.3
uvm2            3760      5396        393     >20.2
uvw2            4787      4986        197     >20.1
white           4580      4780        197     >21.4
---------------------------------------------------

    The quoted upper limits have not been corrected for the expected
extinction due to the Galactic reddening along the line of sight to
this burst of E(B-V) = 0.05 mag (Schlafly et al. 2011, ApJS, 737,
103).