NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 211024d11h33m03s071876usUT
NOTE: Source region spec. is: 170.30963 39.13578 3"
NOTE: Used archived uvot source position of 170.30963  39.13578  3.00
NOTE: position reference is GCN_Circ_30960
NOTE: A UVOT position was reported in GCN_Circ_30960
NOTE: Possible detection in uu at T+310.3
NOTE: Possible detection in wh at T+97.5

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

GRB 211023B: Swift/UVOT Upper Limits

N. P. M. Kuin (UCL-MSSL) and S. Dichiara (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 211023B
98 s after the BAT trigger (Dichiara et al., GCN Circ. 30960).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 30966)
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            98          247          147         >19.1
u_FC               310          560          246         >19.0
white               98         1703          412         >19.7
v                  640         1753          136         >18.8
b                  566         1679          117         >19.9
u                  310         1828          343         >19.2
w1                 690         1803          117         >19.3
w2                 615         1039           39         >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.024 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 211023B: Swift/UVOT Detection

N. P. M. Kuin (UCL-MSSL) and S. Dichiara (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 211023B
98 s after the BAT trigger (Dichiara et al., GCN Circ. 30960).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 30966)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  11:21:14.33 = 170.30971 (deg.)
    Dec (J2000) = +39:08:08.8  =  39.13579 (deg.)
with an estimated uncertainty of 0.53 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               98          247          147         19.44 +/- 0.11
v                  640         1753          136        >18.8
b                  566         1679          117        >19.9
u                  310          734          265         19.50 +/- 0.20
w1                 690         1803          117        >19.3
w2                 615         1039           39        >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.024 in the direction of the burst
(Schlegel et al. 1998).