TITLE:   GCN CIRCULAR
NUMBER:  5993
SUBJECT: GRB 070103: Swift/UVOT Upper limits
DATE:    07/01/04 15:42:47 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/GSFC/USRA) and T. Sakamoto (NASA/ORAU)
report on the behalf of the Swift UVOT team:


      The Swift/UVOT observed the field of GRB 070103 starting 55 s
after the BAT trigger (Sakamoto et al. 2007, GCN Circ. 5988).  We do
not find any source, in any of the UVOT observations, inside the
refined XRT error circle (Mangano et al., 2007 GCN Circ. 5992).

      The 3-sigma upper limits for detecting a source anywhere inside
the XRT error circle in the V-band settling image, the finding-chart
exposures, and the co-added frames are:


Filter         T_start   T_stop    Exp(s)    Mag (3-sigma upper limit)
-----------------------------------------------------------------
V settling          55       65       9      16.5
V finding          180      580     393      19.6
V finding          857     1257     393      19.6
White finding       75      175      98      19.8

V                   55   23,730    2881      20.8
B                 5652   30,281    1235      21.3
U                  634   36,065    3344      21.6
UVW1               610   35,291    3778      21.5
UVM2               586   34,384    2930      21.4
UVW2               686   22,816    1318      21.0
White               75     6056     411      20.7
-----------------------------------------------------------------

The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.07 mag towards
the direction of the burst (Schlegel et al. 1998).