NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250905d11h40m23s183367usUT
NOTE: Source region spec. is: 233.00558 0.79369 4"
NOTE: Used archived XRT position of 233.00558   0.79369  4.00
NOTE: position reference is GCN_Circulars-41722

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

GRB 250905A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and Brivio (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250905A
140 s after the BAT trigger (Brivio et al., GCN Circ. 41714).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-41722 ***
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 first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC           140          290          147         >20.5
white              140          290          147         >20.5
u                  300          405          103         >19.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.054 in the direction of the burst
(Schlegel et al. 1998).