NOTE: uvot_fluxes_wget.pl vrs. 2018-01-16 fem at 180204d20h28m49s178694usUT
NOTE: Source region spec. is: 330.13329 30.83783 4"
NOTE: Used archived XRT position of 330.13329  30.83783  4.00
NOTE: position reference is GCN_Circulars-22377
NOTE: Possible detection in wh at T+17520.1 sum
NOTE: Possible detection in vv at T+9983.2

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

GRB 180204A: Swift/UVOT Upper Limits

N. P. M. Kuin (UCL-MSSL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180204A
92 s after the BAT trigger (Page et al., GCN Circ. 22375).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 22377)
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            92          242          147         >20.3
u_FC               304          554          246         >19.9
white               92        17884         1210         >20.8
v                  633        10587         1107         >19.0
b                  559        23622         1840         >20.7
u                  304        29359         2718         >21.2
w1                3943        29036         2803         >21.1
m2                 658        28130         1981         >20.7
w2                 609         6398          413         >20.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.10 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 180204A: Swift/UVOT Detection

N. P. M. Kuin (UCL-MSSL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180204A
92 s after the BAT trigger (Page et al., GCN Circ. 22375).
A source consistent with the XRT position
(Osborne et al. GCN Circ. 22377)
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               92        17884         1210         21.49 +/- 0.28
v                 9983        10283          295         18.86 +/- 0.25
b                  559        23622         1840        >20.7
u                  304        29359         2718        >21.2
w1                3943        29036         2803        >21.1
m2                 658        28130         1981        >20.7
w2                 609         6398          413        >20.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.10 in the direction of the burst
(Schlegel et al. 1998).