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

GRB 150902A: Swift/UVOT Upper Limits

A. A. Breeveld (UCL-MSSL) and B. Sbarufatti (INAF-OAB/PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150902A
59510 s after the LAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the LAT position
*** POSITION REFERENCE is GCN_Circ-18228 ***
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            60331        78627         1365         >21.5
v                61152        73483         1261         >19.9
u                59510        78306         2054         >20.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.40 in the direction of the burst
(Schlegel et al. 1998).