GCN Circular 14323

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

     Swift/UVOT began settled observations of the field of GRB 130315A
starting 171 s after the BAT trigger (Evans et al., 2013, GCNC 14311).
We do not detect any new source within the XRT error circle (Page et al.,
2013, GCNC 14317).  Preliminary UVOT 3-sigma upper limits at this
position are presented below.

------------------------------------------------
Filter      TSTART     TSTOP    Exposure     Mag
------------------------------------------------
white (FC)     171       321         147   >21.1 
    u (FC)     330       580         246   >20.3 
------------------------------------------------
    v         4476    23,657        1136   >20.7 
    b         3860    28,925        1685   >21.7 
    u          330    17,889        1443   >21.4 
 uvw1         4887    17,764        1995   >21.3 
 uvm2         4681    16,857        1277   >21.0 
 uvw2         4271    22,898        1279   >21.2 
white          171    29.424        1022   >22.2 
------------------------------------------------

    The quoted upper limits have not been corrected for the Galactic
extinction along the line of sight to this burst of E_{B-V} = 0.32 mag
(Schlafly et al. 2011, ApJS, 737, 103).  The photometry is in the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373).
The photometry is affected by the presence of a J = 15.4 mag 2MASS
source 10301128-5147395 located 2.3 arcsec south of the XRT position.