NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250628d08h42m43s880474usUT
NOTE: Source region spec. is: 38.55312 -38.07894 4"
NOTE: Used archived XRT position of  38.55312 -38.07894  4.00
NOTE: position reference is GCN_Circulars-40854

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

GRB 250628A: Swift/UVOT Upper Limits

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

The Swift/UVOT began settled observations of the field of GRB 250628A
130 s after the BAT trigger (Ferro et al., GCN Circ. 40853).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-40854 ***
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           130          280          147         >20.8
u_FC               342          591          246         >19.3
white              130          641          167         >20.8
v                  671          691           19         >17.8
b                  597          617           19         >18.5
u                  342          591          246         >19.3
w1                 720          740           19         >18.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.023 in the direction of the burst
(Schlegel et al. 1998).