NOTE: uvot_fluxes_wget.pl vrs. 2020-10-20 fem at 201022d14h35m36s778142usUT
NOTE: Source region spec. is: 12.52886 -55.86577 3"
NOTE: Used archived uvot source position of  12.52886 -55.86577  3.00
NOTE: position reference is GCN_Circ_28745
NOTE: A UVOT position was reported in GCN_Circ_28745
NOTE: Possible detection in uu at T+318.1
NOTE: Possible detection in wh at T+105.9
NOTE: Possible detection in bb at T+573.9
NOTE: Possible detection in vv at T+647.9

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

GRB 201021C: Swift/UVOT Upper Limits

S. R. Oates (U.Warwick) 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 201021C
106 s after the BAT trigger (Lien et al., GCN Circ. 28730).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 28736)
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           106          256          147         >16.6
u_FC               318          568          246         >15.7
white              106          917          228         >16.6
v                  648          842           39         >16.2
b                  574          767           39         >16.7
u                  318          742          265         >15.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 201021C: Swift/UVOT Detection

S. R. Oates (U.Warwick) 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 201021C
106 s after the BAT trigger (Lien et al., GCN Circ. 28730).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 28736)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  00:50:06.93 =  12.52886 (deg.)
    Dec (J2000) = -55:51:56.8  = -55.86577 (deg.)
with an estimated uncertainty of 0.42 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              106          256          147         16.70 +/- 0.03
v                  648          668           20         16.55 +/- 0.15
b                  574          594           20         16.84 +/- 0.10
u                  318          568          246         15.81 +/- 0.03

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).