NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250330d13h22m19s216959usUT
NOTE: Source region spec. is: 252.93713 -86.87994 4"
NOTE: Used archived XRT position of 252.93713 -86.87994  4.00
NOTE: position reference is GRB_Auto_Processing

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

GRB 250330A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250330A
3944 s after the BAT trigger (Cenko et al., GCN Circ. 39938).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GRB_Auto_Processing ***
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          3944         4094          147         >21.2
white             3944         4094          147         >21.2
v                 4101         4300          197         >20.0
b                 4921         5109          185         >20.9
u                 4716         4915          197         >20.0
w1                4511         4711          197         >21.3
m2                4306         4505          197         >19.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.147 in the direction of the burst
(Schlegel et al. 1998).