NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250531d06h28m20s822953usUT
NOTE: Source region spec. is: 55.17083 -22.44800 4"
NOTE: Used archived XRT position of  55.17083 -22.44800  4.00
NOTE: position reference is GCN_Circulars-40586

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

GRB 250530C: Swift/UVOT Upper Limits

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

The Swift/UVOT began settled observations of the field of GRB 250530C
112 s after the BAT trigger (Caputo et al., GCN Circ. 40585).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-40586 ***
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           112          262          147         >20.7
u_FC               272          521          246         >20.4
white              112          743          186         >20.9
v                  601         5252          216         >18.8
b                  527         5944          109         >19.8
u                  272         5867          462         >20.7
w1                 650         5662          216         >19.6
m2                5257         5457          197         >20.3
w2                 577         5048          216         >19.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.025 in the direction of the burst
(Schlegel et al. 1998).