GCN Circular 32875
Subject
GRB 221027B: Swift/UVOT Upper Limits
Event
Date
2022-10-28T15:11:15Z (3 years ago)
From
Alexander Belles at PSU/Swift <aub1461@psu.edu>
A. Belles (PSU) and A. Y. Lien (U. Tampa)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 221027B
131 s after the BAT trigger (Lien et al., GCN Circ. 32867).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 32868)
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 131 281 147 >21.1
u_FC 344 594 246 >20.2
white 131 1544 392 >21.5
v 673 1594 117 >19.2
b 599 1520 97 >19.4
u 344 1661 335 >20.4
w1 722 1644 97 >18.8
m2 698 718 19 >17.6
w2 111 841 30 >19.2
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.033 in the direction of the burst
(Schlegel et al. 1998).