NOTE: A UVOT position was reported in GCN_Circulars-xxxxx
NOTE: Possible detection in wh at T+33589.9

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

GRB 150523A: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150523A
32968 s after the LAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 17866)
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 initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white            33590        39627         1150         >21.2
v                34212        40619         1433         >20.5
u                32968        44748         2077         >20.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.30 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 150523A: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150523A
32968 s after the LAT trigger (***Author*** et al., GCN Circ. ????).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 17866)
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            33590        39627         1150         21.83 +/- 0.24
v                34212        40619         1433        >20.5
u                32968        44748         2077        >20.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.30 in the direction of the burst
(Schlegel et al. 1998).