NOTE: uvot_fluxes_wget.pl vrs. 2024-08-27 fem at 250807d23h50m48s925214usUT
NOTE: Source region spec. is: 15.63741 -59.11887 3"
NOTE: Used archived uvot source position of  15.63741 -59.11887  3.00
NOTE: position reference is GCN_Circ_41268
NOTE: A UVOT position was reported in GCN_Circ_41268
NOTE: Possible detection in wh at T+153.6
NOTE: Possible detection in uu at T+312.8

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

GRB 250807B: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and N. J. Klingler (GSFC/UMBC/CRESSTII)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250807B
154 s after the BAT trigger (Klingler et al., GCN Circ. 41268).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-41272 ***
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           154          303          147         >16.3
white              154          303          147         >16.3
u                  313          339           26         >14.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.016 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 250807B: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and N. J. Klingler (GSFC/UMBC/CRESSTII)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250807B
154 s after the BAT trigger (Klingler et al., GCN Circ. 41268).
A source consistent with the XRT position
*** POSITION REFERENCE is GCN_Circulars-41272 ***
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  01:02:33.00 =  15.63751 (deg.)
    Dec (J2000) = -59:07:08.6  = -59.11906 (deg.)
with an estimated uncertainty of 0.42 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              154          303          147         16.35 +/- 0.03
u                  313          339           26         15.12 +/- 0.06

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.016 in the direction of the burst
(Schlegel et al. 1998).