NOTE: uvot_fluxes_wget.pl vrs. 2023-03-23 fem at 230409d12h24m16s153412usUT
NOTE: Source region spec. is: 329.51475 52.83211 4"
NOTE: Used archived XRT position of 329.51475  52.83211  4.00
NOTE: position reference is GCN_Circulars-33594
NOTE: Possible detection in wh at T+386.4

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

GRB 230409B: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and A. P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230409B
386 s after the BAT trigger (Beardmore et al., GCN Circ. 33592).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 33594)
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           386          536          147         >19.3
white              386         1362          373         >19.4
v                  542         1931          156         >18.2
b                  642         2029          156         >19.3
u                  616         2004          156         >19.0
w1                 592         1980          156         >18.8
m2                 567         1955          156         >19.0
w2                 692         2077          153         >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.226 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 230409B: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and A. P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230409B
386 s after the BAT trigger (Beardmore et al., GCN Circ. 33592).
A source consistent with the XRT position
(Evans et al. GCN Circ. 33594)
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              386          859          186         19.78 +/- 0.20
v                  542         1931          156        >18.2
b                  642         2029          156        >19.3
u                  616         2004          156        >19.0
w1                 592         1980          156        >18.8
m2                 567         1955          156        >19.0
w2                 692         2077          153        >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.226 in the direction of the burst
(Schlegel et al. 1998).