[vsnet-grb-info 15009] GRB 140518A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16303
SUBJECT: GRB 140518A: Swift/UVOT Upper Limits
DATE:    14/05/18 17:18:01 GMT
FROM:    Paul Kuin at MSSL  <npkuin at gmail.com>

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

The Swift/UVOT began settled observations of the field of
GRB 140518A  77 s after the BAT trigger (Melandri et al.,
GCN Circ. 16298).  No optical afterglow consistent with the
XRT position (Melandri et al. GCN Circ. 16298) 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          226          147         >20.7
u_FC               289          539          246         >20.7
white               77        13719         1583         >22.6
v                  619         7499          568         >20.2
b                  545        12953         1060         >22.0
u                  289        12041         1286         >21.6
w1                 668         7910          568         >21.4
m2                1071         7705          413         >21.1
w2                 595         7295          510         >21.3

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).