GCN Circular 15084

S. T. Holland (STScI) and B. P. Gompertz (U Leicester) report on
behalf of the Swift/UVOT team:

    The Swift/UVOT began settled observations of the field of GRB
130806A starting 69 s after the BAT trigger (Gompertz et al. 2013,
GCNC 15071).  We do not detect any new source consistent with the
UVOT-enhanced XRT position (Beardmore et al. 2013, GCNC 15072) 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 (FC) exposures and initial summed exposures
are presented below.

-------------------------------------------------
Filter      TSTART      TSTOP   Exposure      Mag
-------------------------------------------------
white (FC)      69        218        147    >20.6
   u (FC)     282        305         23    >18.2
-------------------------------------------------
   b         3571     11,831       1028    >21.3           
   u         4801     11,172       1082    >21.4
   v         4187       5823        393    >19.9
uvw1         4597     10,259       1116    >21.2
uvm2         4391     15,843       1066    >20.9
uvw2         3982       5618        393    >20.7
white         3776       5411        393    >21.8
-------------------------------------------------

    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) = 1.02 mag (Schlafly et al. 2011, ApJS, 737,
103).  GRB 130806A was 6 degrees above the Galactic Plane, so this
extinction value is highly uncertain.