GCN Circular 31328
Subject
GRB 211227A: Swift/UVOT Upper Limits
Date
2021-12-28T19:38:09Z (2 years ago)
From
Alexander Belles at PSU/Swift <aub1461@psu.edu>
A. Belles (PSU) 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 211227A
82 s after the BAT trigger (Beardmore et al., GCN Circ. 31316).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 31322)
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 82 232 147 >19.4
u_FC 294 544 246 >19.2
white 82 1021 334 >19.5
v 624 4923 241 >18.7
b 550 742 39 >18.6
u 294 5431 357 >19.4
w1 673 5333 235 >19.7
m2 648 5127 235 >20.4
w2 772 792 19 >19.0
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.020 in the direction of the burst
(Schlegel et al. 1998).