TITLE:   GCN CIRCULAR
NUMBER:  8874
SUBJECT: GRB090201: Swift UVOT upper limits
DATE:    09/02/02 11:05:00 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and S. Oates (MSSL-UCL) report on behalf of the  
Swift UVOT team

The Swift/UVOT began settled observations of the field of GRB 090201  
3668s after the BAT trigger (Oates et al., GCN 8865). We do not detect  
any source at the enhanced Swift XRT position (Beardmore et al. GCN  
8872) or at the VLT optical and NIR afterglow candidate (D'Avanzo et  
al. GCN 8873) down to the following 3-sigma upper limits:

Filter    T_start(s)   T_stop(s)  Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
White     3668           5051       344       > 21.53
v             3825          10589      1159    > 20.63
b             4646          16906      834      > 21.38
u             4440          16245      1082    > 21.15
uvw1      4235          14730      448      > 20.16
uvm2     4030           11123     717       > 20.53
uvw2      5056          5256        197       > 20.03

The quoted upper limits have not been corrected for the expected  
Galactic extinction along the line of sight of E_(B-V) = 0.07 mag. All  
photometry is on the UVOT photometric system described in Poole et al.  
(2008, MNRAS, 383, 627).