GCN Circular 33211
Subject
GRB 230123A: Swift/UVOT Upper Limits
Date
2023-01-23T19:25:47Z (a year ago)
From
Alexander Belles at PSU/Swift <aub1461@psu.edu>
A. Belles (PSU) and M. Williams (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 230123A
93 s after the BAT trigger (Williams et al., GCN Circ. 33206).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 33209)
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 93 243 147 >20.6
u_FC 305 555 246 >20.6
white 93 1704 412 >21.0
v 637 1754 136 >19.4
b 562 1679 117 >20.0
u 305 1825 359 >20.5
w1 686 1804 117 >20.8
m2 1412 1605 39 >18.7
w2 612 1209 78 >20.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.022 in the direction of the burst
(Schlegel et al. 1998).