GCN Circular 16303

Subject

GRB 140518A: Swift/UVOT Upper Limits

Event

Date

2014-05-18T17:18:01Z (12 years ago)

From

Paul Kuin at MSSL <npkuin@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. 16298Loading...
 
 ).  No optical afterglow consistent with the
XRT position (Melandri et al. GCN Circ. 16298Loading...
 
 ) 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).