NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210208d02h03m12s550440usUT
NOTE: Source region spec. is: 270.63501 53.68223 3"
NOTE: Used archived uvot source position of 270.63501  53.68223  3.00
NOTE: position reference is GCN_Circ_29420
NOTE: A UVOT position was reported in GCN_Circ_29420
NOTE: Possible detection in uu at T+294.5
NOTE: Possible detection in wh at T+82.5

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

GRB 210207B: Swift/UVOT Upper Limits

M. H. Siegel (PSU) 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 210207B
82 s after the BAT trigger (Lien et al., GCN Circ. 29420).
No optical afterglow consistent with the XRT position
(Lien et al. GCN Circ. 29420)
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            82          232          147         >13.0
white               82          232          147         >13.0
u                  294          410          113         >14.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.041 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 210207B: Swift/UVOT Detection

M. H. Siegel (PSU) 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 210207B
82 s after the BAT trigger (Lien et al., GCN Circ. 29420).
A source consistent with the XRT position
(Lien et al. GCN Circ. 29420)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  18:02:32.40 = 270.63500 (deg.)
    Dec (J2000) = +53:40:55.8  =  53.68217 (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               82          232          147         13.09 +/- 0.05
u                  294          410          113         14.47 +/- 0.03

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.041 in the direction of the burst
(Schlegel et al. 1998).