TITLE:   GCN CIRCULAR
NUMBER:  18017
SUBJECT: GRB 150711A: Swift/UVOT Upper Limits
DATE:    15/07/12 09:05:59 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and M. G. Bernardini (INAF-OAB) report
on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150711A
117 s after the BAT trigger (Bernardini et al., GCN Circ. 18011).
No optical afterglow consistent with the XRT position (Osborne et al.
GCN Circ. 18012)  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           117          267          147         >21.4
u_FC               330          580          246         >20.2
white              117          909          235         >21.9
v                  660          852           39         >19.0
b                  585          778           39         >19.9
u                  330          753          265         >20.2
w1                 709          729           19         >18.8
m2                 684          704           19         >18.9
w2                 636          828           39         >18.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.09 in the direction of the burst
(Schlegel et al. 1998).