NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 241025d05h40m32s230051usUT
NOTE: Source region spec. is: 28.84754 5.93833 3"
NOTE: Used archived opt source position of  28.84754   5.93833  3.00
NOTE: position reference is GCN_Circulars-37840

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

GRB 241021A: Swift/UVOT Upper Limits

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

The Swift/UVOT began settled observations of the field of GRB 241021A
316188 s after the EP trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the optical position
*** POSITION REFERENCE is GCN_Circulars-37840 ***
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 initial exposures are:

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

v               316188       327327         2546         >20.8
b               316793       316959          163         >20.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.053 in the direction of the burst
(Schlegel et al. 1998).