GCN Circular 34941
Subject
GRB 231104A: Swift/UVOT Upper Limits
Date
2023-11-04T12:44:11Z (6 months ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Via
email
N. P. M. Kuin (UCL/MSSL) and K. L. Page (U. Leicester) report on behalf
of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 231104A
91 s after the BAT trigger (Page et al., GCN Circ. 34940). No optical
afterglow consistent with the XRT position (Goad et al., GCN Circ. 34940)
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 91 241 147 >21.7
u_FC 304 553 246 >20.7
white 91 1709 411 >21.8
v 633 1758 117 >19.3
b 559 1684 117 >20.4
u 304 1659 343 >20.9
w1 683 1808 117 >19.7
m2 659 679 20 >18.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.156 in the direction of the burst
(Schlegel et al. 1998).