TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5536
SUBJECT: GRB 060906: Swift-UVOT observations
DATE:    06/09/06 18:31:26 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and J.L. Racusin (PSU) report on behalf of the
Swift-UVOT team:

The Swift UVOT began observing GRB 060906 152 seconds after the BAT
trigger (GCN 5528). No optical afterglow is detected at the 3-sigma level
in the XRT error circle (GCN 5528) or at the location of the afterglow reported 
by Cenko et al. (GCN 5529) in individual or coadded exposures of any of the 
UVOT filters.

The 3-sigma limiting magnitudes for the coadded images of the
UVOT filters are listed below:

Filter  T_range(s)      Exp(s)  Upper limit (3sig)
WHITE   201-8121        583     20.6
V       457-7210        1297    20.1
B       739-8029        520     20.3
U       720-7824        529     20.0
W1      697-7619        549     19.6
M2      672-7415        549     19.9
W2      773-7006        320     19.7

where T_range is the start and end times of the coadded exposures. No
correction has been made for Galactic reddening along the line of sight
(E(B-V) = 0.20 mag).