NOTE: uvot_fluxes_wget.pl vrs. 2020-10-20 fem at 201021d21h48m30s272406usUT
NOTE: Source region spec. is: 75.47000 77.06840 3"
NOTE: Used archived opt source position of  75.47000  77.06840  3.00
NOTE: position reference is GCN_Circulars-28719
NOTE: Possible detection in uu at T+72101.8
NOTE: Possible detection in wh at T+73636.3
NOTE: Possible detection in vv at T+73979.2

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

GRB 201020: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201020
72102 s after the LAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the optical position
(Xu et al. GCN Circ. 28719)
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 initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white            73636        73973          331         >19.5
v                73979        74316          331         >19.0
u                72102        73631         1039         >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.15 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 201020: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201020
72102 s after the LAT trigger (***Author*** et al., GCN Circ. ????).
A source consistent with the optical position
(Xu et al. GCN Circ. 28719)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  05:01:52.86 =  75.47026 (deg.)
    Dec (J2000) = +77:04:05.8  =  77.06828 (deg.)
with an estimated uncertainty of 0.53 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            73636        73973          332         19.67 +/- 0.07
v                73979        74316          331         19.54 +/- 0.22
u                72102        72821          708         19.27 +/- 0.09

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.15 in the direction of the burst
(Schlegel et al. 1998).