NOTE: uvot_fluxes_wget.pl vrs. 2023-03-23 fem at 240408d20h19m16s930474usUT
NOTE: Source region spec. is: 236.9760 -62.5656 4"
NOTE: Used archived XRT position of 236.97600 -62.56560  4.00
NOTE: position reference is GCN_Notice
NOTE: Possible detection in bb at T+555.4
NOTE: Possible detection in uu at T+299.6
NOTE: Possible detection in wh at T+141.4

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

GRB 240408: Swift/UVOT Upper Limits

A. A. Breeveld (UCL-MSSL) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240408
141 s after the BAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Notice ***
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           141          291          147         >17.4
u_FC               300          549          246         >17.5
white              141          594          161         >17.4
b                  555          575           19         >16.8
u                  300          549          246         >17.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.287 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 240408: Swift/UVOT Detection

A. A. Breeveld (UCL-MSSL) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240408
141 s after the BAT trigger (***Author*** et al., GCN Circ. ????).
A source consistent with the XRT position
*** POSITION REFERENCE is GCN_Notice ***
is detected in the initial UVOT exposures.

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              141          291          147         17.51 +/- 0.04
b                  555          575           20         17.18 +/- 0.13
u                  300          549          246         17.68 +/- 0.07

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.287 in the direction of the burst
(Schlegel et al. 1998).