NOTE: uvot_fluxes_wget.pl vrs. 2018-11-07 fem at 190204d23h28m04s462716usUT
NOTE: Source region spec. is: 351.47742 54.87637 3"
NOTE: Used archived uvot source position of 351.47742  54.87637  3.00
NOTE: position reference is GCN_Circ_23852
NOTE: A UVOT position was reported in GCN_Circ_23852
NOTE: Possible detection in uu at T+295.8
NOTE: Possible detection in wh at T+83.5
NOTE: Possible detection in bb at T+551.2
NOTE: Possible detection in w1 at T+5363.1 sum
NOTE: Possible detection in vv at T+626.2

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

GRB 190204A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190204A
84 s after the BAT trigger (Lien et al., GCN Circ. 23852).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 23862)
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            84          233          147         >16.7
u_FC               296          546          246         >17.6
white               84        24124         1679         >19.1
v                  626        17182         1376         >19.3
b                  551        23910         2142         >20.4
u                  296        22998         1602         >19.2
w1                 676        18762         1147         >20.0
m2                 651        18088         1376         >20.9
w2                 602        13026         1215         >20.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.38 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 190204A: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190204A
84 s after the BAT trigger (Lien et al., GCN Circ. 23852).
A source consistent with the XRT position
(Osborne et al. GCN Circ. 23862)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  23:25:54.50 = 351.47708 (deg.)
    Dec (J2000) = +54:52:35.9  =  54.87665 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

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               84          233          147         16.77 +/- 0.03
v                  626         1247           78         18.28 +/- 0.23
b                  551         1520           97         19.33 +/- 0.20
u                  296          546          246         17.79 +/- 0.07
w1                 676         5563          294         19.68 +/- 0.32
m2                 651        18088         1376        >20.9
w2                 602        13026         1215        >20.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.38 in the direction of the burst
(Schlegel et al. 1998).