TITLE:   GCN CIRCULAR
NUMBER:  16460
SUBJECT: GRB 140626A: Swift/UVOT Upper Limits
DATE:    14/06/26 12:44:27 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and J. R. Cummings (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 140626A
103 s after the BAT trigger (Cummings et al., GCN Circ. 16456).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 16459)
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           103          253          147         >20.9
u_FC               262          511          246         >20.3
white              103         1538          392         >21.1
v                  592         1590          117         >19.0
b                  517         1514           97         >20.0
u                  262         1489          343         >20.4
w1                 642         1639          117         >19.4
m2                 617         1440           39         >19.1
w2                 568         1563          117         >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.15 in the direction of the burst
(Schlegel et al. 1998).