NOTE: uvot_fluxes_wget.pl vrs. 2018-01-16 fem at 180926d02h12m31s903443usUT
NOTE: Source region spec. is: 315.20075 -64.45689 4"
NOTE: Used archived XRT position of 315.20075 -64.45689  4.00
NOTE: position reference is GCN_Circulars-23271
NOTE: Possible detection in uu at T+277.3
NOTE: Possible detection in wh at T+119.4
NOTE: Possible detection in bb at T+1832.3 sum
NOTE: Possible detection in vv at T+5718.9

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

GRB 180925A: Swift/UVOT Upper Limits

S.W.K. Emery (UCL-MSSL) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180925A
119 s after the BAT trigger (Gropp et al., GCN Circ. 23268).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 23271)
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         >19.3
u_FC               277          527          246         >18.9
white              119         6943          822         >19.6
v                  607         7354          549         >18.8
b                  533         6739          347         >19.5
u                  277         6533          579         >19.2
w1                 657         7755          540         >19.7
m2                1062         7559          432         >19.9
w2                 583         7149          490         >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 180925A: Swift/UVOT Detection

S.W.K. Emery (UCL-MSSL) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180925A
119 s after the BAT trigger (Gropp et al., GCN Circ. 23268).
A source consistent with the XRT position
(Goad et al. GCN Circ. 23271)
is detected in the initial UVOT exposures.

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              119          269          147         19.64 +/- 0.12
v                  607         7354          549         19.28 +/- 0.20
b                  533         6739          347         19.95 +/- 0.18
u                  277          527          246         19.41 +/- 0.19
w1                 657         7755          540        >19.7
m2                1062         7559          432        >19.9
w2                 583         7149          490        >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).