NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250920d22h27m52s339453usUT
NOTE: Source region spec. is: 51.46442 -29.65661 4"
NOTE: Used archived XRT position of  51.46442 -29.65661  4.00
NOTE: position reference is GCN_Circulars-41904
NOTE: Possible detection in wh at T+130.8

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

GRB 250920C: Swift/UVOT Upper Limits

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

The Swift/UVOT began settled observations of the field of GRB 250920C
131 s after the BAT trigger (Gupta et al., GCN Circ. 41904).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-41904 ***
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

white              131          195           63         >18.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.018 in the direction of the burst
(Schlegel et al. 1998).


=========== Draft Detection Circular ========

GRB 250920C: Swift/UVOT Detection

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

The Swift/UVOT began settled observations of the field of GRB 250920C
131 s after the BAT trigger (Gupta et al., GCN Circ. 41904).
A source consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-41904 ***
is detected in the initial UVOT exposures.

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: 

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

white              131          195           63         18.39 +/- 0.08

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.018 in the direction of the burst
(Schlegel et al. 1998).