NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 220306d21h32m48s622358usUT
NOTE: Source region spec. is: 5.38792 71.36361 4"
NOTE: Used archived XRT position of   5.38792  71.36361  4.00
NOTE: position reference is GCN_Circulars-31700
NOTE: Possible detection in wh at T+881.2 sum

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

GRB 220306B: Swift/UVOT Upper Limits

M. H. Siegel (PSU) and Caputo (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220306B
89 s after the BAT trigger (Caputo et al., GCN Circ. 31697).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 31700)
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            89          239          147         >19.9
u_FC               302          552          246         >20.1
white               89         1716          402         >20.4
v                  631         1601          117         >18.7
b                  557         1701          117         >19.9
u                  302         1676          343         >20.2
w1                 680         1650          117         >19.3
m2                 656         1626          117         >19.4
w2                 607         5204          213         >19.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.578 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 220306B: Swift/UVOT Detection

M. H. Siegel (PSU) and Caputo (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220306B
89 s after the BAT trigger (Caputo et al., GCN Circ. 31697).
A source consistent with the XRT position
(Evans et al. GCN Circ. 31700)
is detected in the initial UVOT exposures.

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               89         1205          353         20.96 +/- 0.32
v                  631         1601          117        >18.7
b                  557         1701          117        >19.9
u                  302         1676          343        >20.2
w1                 680         1650          117        >19.3
m2                 656         1626          117        >19.4
w2                 607         5204          213        >19.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.578 in the direction of the burst
(Schlegel et al. 1998).