GCN Circular 18517
Subject
GRB 151027B: Swift/UVOT Upper Limits
Event
Date
2015-10-28T15:45:21Z (11 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and T. N. Ukwatta (LANL) report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 151027B
210 s after the BAT trigger (Ukwatta et al., GCN Circ. 18499).
No optical afterglow consistent with the XRT position (Osborne et al.
GCN Circ. 18504) 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 210 359 147 >20.0
white 210 4545 344 >20.5
v 366 4956 216 >18.8
b 4141 5737 354 >20.6
u 3935 5571 393 >20.4
w1 415 5366 397 >20.4
m2 4961 5161 197 >19.1
w2 4551 4751 197 >19.9
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.25 in the direction of the
burst (Schlegel et al. 1998).