TITLE:   GCN CIRCULAR
NUMBER:  17447
SUBJECT: GRB 150211A: Swift/UVOT Upper Limits
DATE:    15/02/12 02:35:34 GMT
FROM:    Margaret Chester at PSU  <chester@swift.psu.edu>

M. M. Chester (Penn State) and R. L. C. Starling (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150211A
2116 s after the BAT trigger (Starling et al., GCN Circ. 17434).
No optical afterglow consistent with the XRT position (Starling 
GCN Circ. 17442) 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          2116         2266          147         >21.3
white             2116         3123          383         >21.8
v                 2272         8220          255         >20.4
b                 2371         2918          236         >20.1
u                 2346         2713           58         >19.7
w1                2321         2688           58         >19.4
m2                8225         8421          193         >20.4
w2                3129         3243          112         >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).