NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250924d21h33m10s694897usUT
NOTE: Source region spec. is: 51.87340 74.65945 3"
NOTE: Used archived uvot source position of  51.87340  74.65945  3.00
NOTE: position reference is GCN_Circ_41959
NOTE: A UVOT position was reported in GCN_Circ_41959
NOTE: Possible detection in uu at T+350.9
NOTE: Possible detection in bb at T+606.5
NOTE: Possible detection in wh at T+192.7

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

GRB 250924A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250924A
193 s after the BAT trigger (Siegel et al., GCN Circ. 41959).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GRB_Auto_Processing ***
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           193          342          147         >17.7
u_FC               351          601          246         >17.8
white              193         1184          353         >18.4
v                  681         1234           58         >18.4
b                  606         1160           58         >18.8
u                  351         1135          285         >17.9
w1                 730         1110           39         >19.0
m2                1065         1085           19         >17.6
w2                 656         1210           78         >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.315 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 250924A: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250924A
193 s after the BAT trigger (Siegel et al., GCN Circ. 41959).
A source consistent with the XRT position
*** POSITION REFERENCE is GRB_Auto_Processing ***
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  03:27:29.66 =  51.87358 (deg.)
    Dec (J2000) = +74:39:34.0  =  74.65945 (deg.)
with an estimated uncertainty of 0.43 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              193          342          147         17.80 +/- 0.04
v                  681         1234           58        >18.4
b                  606          626           19         18.75 +/- 0.30
u                  351          601          246         18.03 +/- 0.08
w1                 730         1110           39        >19.0
m2                1065         1085           19        >17.6
w2                 656         1210           78        >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.315 in the direction of the burst
(Schlegel et al. 1998).