GCN Circular 29590
Subject
GRB 210226A: Swift/UVOT Upper Limits
Date
2021-02-28T23:29:56Z (4 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and A. P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210226A
102 s after the BAT trigger (Beardmore et al., GCN Circ. 29568).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 29568)
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 102 251 147 >20.9
u_FC 314 563 246 >20.4
white 102 1192 353 >21.4
v 643 1236 72 >19.1
b 569 1167 58 >19.9
u 314 5121 463 >20.5
w1 692 4935 236 >20.4
m2 4530 4730 197 >20.0
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.049 in the direction of the burst
(Schlegel et al. 1998).