NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210705d19h35m32s512143usUT
NOTE: Source region spec. is: 159.02221 57.21636 4"
NOTE: Used archived XRT position of 159.02221  57.21636  4.00
NOTE: position reference is GCN_Circulars-30379

=========== Draft Upper Limit Circular ========

GRB 210704: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210704
53458 s after the LAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the XRT position
(D'Ai et al. GCN Circ. 30379)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

v                53458        72068         3038         >21.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.007 in the direction of the burst
(Schlegel et al. 1998).