TITLE:   GCN CIRCULAR
NUMBER:  18650
SUBJECT: GRB 151127A: Swift/UVOT Upper Limits
DATE:    15/11/27 18:22:40 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K Emery (UCL-MSSL) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 151127A
77 s after the BAT trigger (D'Ai et al., GCN Circ. 18643).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 18647)
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            77          227          147         >20.8
white               77         1017          295         >21.2
w1                 668         6559          452         >20.3
m2                 816         6354          432         >20.0
w2                 594        18458         1696         >21.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.12 in the direction of the burst
(Schlegel et al. 1998).