NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 251001d18h06m52s813366usUT
NOTE: Source region spec. is: 42.65100 -23.02014 4"
NOTE: Used archived XRT position of  42.65100 -23.02014  4.00
NOTE: position reference is GCN_Circulars-42039
NOTE: Possible detection in uu at T+331.0
NOTE: Possible detection in wh at T+118.8

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

GRB 251001B: 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 251001B
119 s after the BAT trigger (Beardmore et al., GCN Circ. 42039).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-42039 ***
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           119          269          147         >18.6
u_FC               331          581          246         >18.4
white              119         1010          295         >18.9
u                  331          581          246         >18.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.023 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 251001B: 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 251001B
119 s after the BAT trigger (Beardmore et al., GCN Circ. 42039).
A source consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-42039 ***
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  02:50:36.30 =  42.65126 (deg.)
    Dec (J2000) = -23:01:11.6  = -23.01990 (deg.)
with an estimated uncertainty of 0.47 arc sec. (radius, 90% confidence).

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              119          269          147         18.76 +/- 0.06
u                  331          581          246         18.75 +/- 0.12

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.023 in the direction of the burst
(Schlegel et al. 1998).