NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250618d21h14m31s169638usUT
NOTE: Source region spec. is: 332.89686 32.73253 3"
NOTE: Used archived uvot source position of 332.89686  32.73253  3.00
NOTE: position reference is GCN_Circ_40778
NOTE: A UVOT position was reported in GCN_Circ_40778
NOTE: Possible detection in vv at T+1303.4 sum
NOTE: Possible detection in w1 at T+2044.5 sum
NOTE: Possible detection in uu at T+1203.7
NOTE: Possible detection in wh at T+796.7
NOTE: Possible detection in bb at T+1228.7

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

GRB 250617B: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250617B
797 s after the BAT trigger (Page et al., GCN Circ. 40760).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-40767 ***
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           797          946          147         >18.1
white              797         2482          448         >18.5
v                 1130         2528          172         >18.2
b                 1229         2458          156         >18.8
u                 1204         2433          156         >18.1
w1                1179         2408          156         >18.7
m2                1155         2384          117         >18.3
w2                1106         2507          175         >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.087 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 250617B: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250617B
797 s after the BAT trigger (Page et al., GCN Circ. 40760).
A source consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-40767 ***
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  22:11:35.25 = 332.89686 (deg.)
    Dec (J2000) = +32:43:57.1  =  32.73253 (deg.)
with an estimated uncertainty of 0.44 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              797          946          147         18.20 +/- 0.05
v                 1130         2528          172         18.71 +/- 0.19
b                 1229         1596           58         18.91 +/- 0.18
u                 1204         1397           39         18.08 +/- 0.19
w1                1179         2408          156         19.33 +/- 0.29
m2                1155         2384          117        >18.3
w2                1106         2507          175        >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.087 in the direction of the burst
(Schlegel et al. 1998).