NOTE: uvot_fluxes_wget.pl vrs. 2018-11-07 fem at 200926d14h09m00s293745usUT
NOTE: Source region spec. is: 246.78521 78.39053 4"
NOTE: Used archived XRT position of 246.78521  78.39053  4.00
NOTE: position reference is GCN_Circulars-28503
NOTE: Possible detection in wh at T+81.7

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

GRB 200925B: Swift/UVOT Upper Limits

S. R. Oates (U.Warwick) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200925B
82 s after the BAT trigger (Cenko et al., GCN Circ. 28499).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 28503)
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            82          231          147         >19.3
u_FC               294          544          246         >19.6
white               82         1714          411         >19.7
v                  623         1763          136         >18.2
b                  549         1689          117         >19.6
u                  294         1663          343         >19.7
w1                 672         1813          136         >19.2
m2                 648         1441           78         >20.2
w2                 599         1739           97         >19.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 200925B: Swift/UVOT Detection

S. R. Oates (U.Warwick) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200925B
82 s after the BAT trigger (Cenko et al., GCN Circ. 28499).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 28503)
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               82         1540          392         20.24 +/- 0.20
v                  623         1763          136        >18.2
b                  549         1689          117        >19.6
u                  294         1663          343        >19.7
w1                 672         1813          136        >19.2
m2                 648         1441           78        >20.2
w2                 599         1739           97        >19.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).