NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250108d01h45m30s191160usUT
NOTE: Source region spec. is: 302.52 45.564 3"
NOTE: Used archived BAT position of 302.52000  45.56400
NOTE: position reference is GCN_Circ-38840

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

GRB 250107A: 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 250107A
125490 s after the GUANO trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the GUANO position
*** POSITION REFERENCE is GCN_Circ-38840 ***
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

white           125490       148537         2996         >21.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.889 in the direction of the burst
(Schlegel et al. 1998).