GCN Circular 33522
Subject
GRB 230325A: Swift/UVOT Upper Limits
Event
Date
2023-03-26T15:23:20Z (3 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N Paul Kuin (UCL/MSSL) and M. J. Moss (GWU)report on behalf
of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of
GRB 230325A 102 s after the BAT trigger (Moss et al., GCN
Circ. 33516). No optical afterglow consistent with the
XRT position (Goad et al. GCN Circ. 33518) 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 102 252 147 >20.1
u_FC 314 540 222 >19.2
white 102 4222 344 >20.8
v 4434 4634 197 >18.9
b 3818 4018 197 >20.0
u 314 5106 277 >19.3
w1 4845 5045 197 >19.9
m2 4640 4839 197 >19.8
w2 4230 4429 197 >20.2
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.046 in the
direction of the burst (Schlegel et al. 1998).