[vsnet-grb-info 18682] GRB 161104A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20130
SUBJECT: GRB 161104A: Swift/UVOT Upper Limits 
DATE:    16/11/05 03:28:35 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

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

The Swift/UVOT began settled observations of the field of GRB 161104A
69 s after the BAT trigger (Mingo et al., GCN Circ. 20123).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 20124)
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 initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white               69          170           99         >20.8
w1                4984         5184          197         >19.9
m2                4779         4979          197         >21.7
w2                5805         6005          197         >19.9

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).