[vsnet-grb-info 17823] GRB 160408A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19267
SUBJECT: GRB 160408A: Swift/UVOT Upper Limits
DATE:    16/04/08 20:15:45 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

M. H. Siegel (PSU) and P. A. Evans (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160408A
98 s after the BAT trigger (Evans et al., GCN Circ. 19260).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 19261) or the possible
optical counterparts (Levan et al., GCN Circ. 19262)
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            98          248          147         >21.0
u_FC               311          561          246         >19.7
white               98         1365          373         >21.8
v                  641         1414           97         >19.4
b                  566         1340           78         >19.6
u                  311         1316          304         >19.9
w1                 691         1291           58         >19.5
m2                 838         1092           39         >18.8
w2                 617         1390           97         >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).