GCN Circular 32085
Subject
GRB 220521A: Swift/UVOT Upper Limits
Date
2022-05-22T13:57:22Z (2 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and S. Dichiara (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220521A
100 s after the BAT trigger (Dichiara et al., GCN Circ. 32076).No optical
afterglow consistent with the XRT position (Evans et al. GCN Circ. 32081)
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 100 250 147 >20.8
u_FC 312 548 232 >19.2
white 100 4178 344 >21.5
v 4389 4589 197 >19.5
b 3773 3973 197 >20.4
u 312 5050 278 >19.4
w1 4798 4998 197 >20.2
m2 4593 4793 197 >19.7
w2 4184 4383 197 >19.7
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.185 in the direction of the burst
(Schlegel et al. 1998).