NOTE: uvot_fluxes_wget.pl vrs. 2018-01-16 fem at 180621d00h56m37s393735usUT
NOTE: Source region spec. is: 357.52126 -57.96224 3"
NOTE: Used archived uvot source position of 357.52126 -57.96224  3.00
NOTE: position reference is GCN_Circ_22807
NOTE: A UVOT position was reported in GCN_Circ_22807
NOTE: Possible detection in uu at T+303.9
NOTE: Possible detection in wh at T+92.0
NOTE: Possible detection in bb at T+559.2
NOTE: Possible detection in vv at T+806.5

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

GRB 180620B: Swift/UVOT Upper Limits

A. A. Breeveld (UCL-MSSL) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180620B
92 s after the BAT trigger (Evans et al., GCN Circ. 22807).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Notice ***
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         >17.9
u_FC               304          554          246         >17.2
white               92          777          186         >17.9
v                  634          826           39         >16.9
b                  559          752           39         >17.5
u                  304          554          246         >17.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 180620B: Swift/UVOT Detection

A. A. Breeveld (UCL-MSSL) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180620B
92 s after the BAT trigger (Evans et al., GCN Circ. 22807).
A source consistent with the XRT position
*** POSITION REFERENCE is GCN_Notice ***
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  23:50:05.11 = 357.52128 (deg.)
    Dec (J2000) = -57:57:43.6  = -57.96210 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).

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               92          242          147         18.04 +/- 0.04
v                  634          826           39         17.41 +/- 0.22
b                  559          579           20         17.48 +/- 0.15
u                  304          554          246         17.35 +/- 0.06

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).