NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 230204d11h24m39s808503usUT
NOTE: Source region spec. is: 238.19962 -50.91653 4"
NOTE: Used archived XRT position of 238.19962 -50.91653  4.00
NOTE: position reference is GCN_Circulars-33261
NOTE: Possible detection in bb at T+1152.0 sum
NOTE: Possible detection in wh at T+156.1
NOTE: Possible detection in vv at T+645.2

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

GRB 230204A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230204A
156 s after the BAT trigger (D'Ai et al., GCN Circ. 33260).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 33261)
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           156          306          147         >17.5
u_FC               314          564          246         >19.1
white              156         1372          373         >17.8
v                  645         1596          117         >15.9
b                  570         1521           97         >17.9
u                  314         5553          382         >19.1
w1                 695         5489          274         >19.1
m2                 670         1446           97         >18.8
w2                 621         1571          117         >18.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 2.516 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 230204A: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230204A
156 s after the BAT trigger (D'Ai et al., GCN Circ. 33260).
A source consistent with the XRT position
(Evans et al. GCN Circ. 33261)
is detected in the initial UVOT exposures.

Preliminary detections and 3-sigma upper limits 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              156          306          147         17.59 +/- 0.04
v                  645          665           20         16.05 +/- 0.15
b                  570         1521           97         18.49 +/- 0.22
u                  314         5553          382        >19.1
w1                 695         5489          274        >19.1
m2                 670         1446           97        >18.8
w2                 621         1571          117        >18.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 2.516 in the direction of the burst
(Schlegel et al. 1998).