NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250510d03h58m04s751818usUT
NOTE: Source region spec. is: 46.44967 -38.84200 4"
NOTE: Used archived XRT position of  46.44967 -38.84200  4.00
NOTE: position reference is GCN_Circulars-40411

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

GRB 250509A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250509A
80 s after the BAT trigger (Siegel et al., GCN Circ. 40407).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-40411 ***
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            80          230          147         >20.1
u_FC               293          542          246         >19.3
white               80         5163          363         >20.9
v                  622         5475          119         >18.5
b                  548         4958          216         >20.1
u                  293         4753          442         >19.8
w1                4349         4548          197         >20.0
w2                5169         5369          197         >20.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.021 in the direction of the burst
(Schlegel et al. 1998).