[vsnet-grb-info 17277] GRB 151122A: Swift/UVOT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18641
SUBJECT: GRB 151122A: Swift/UVOT Observations
DATE:    15/11/24 18:09:00 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 151122A
102884 s after the BAT trigger (Palmer et al., GCN Circ. 18637).
No optical afterglow consistent with either of the XRT positions
given by Evans et al. (GCN Circ 18640) is detected in the initial UVOT exposures.
For source 1, we do not detect any new source down to the detection limit.
For source 2, we only detect the bright high proper motion star HD 189004.

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

w2              102884       113997         2933         >21.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.20 in the direction of the burst
(Schlegel et al. 1998).