GCN Circular 31483
Subject
GRB 220117B: Swift/UVOT Upper Limits
Date
2022-01-18T14:15:21Z (2 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and A. Melandri (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220117B 104 s after the BAT trigger
(Melandri et al., GCN Circ. 31468).
No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 31473) 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 104 254 147 >19.7
white 104 3930 344 >20.5
v 4141 4341 197 >19.2
b 3525 5048 281 >20.7
u 262 4957 239 >19.8
w1 4552 4752 197 >20.0
m2 4346 4546 197 >20.3
w2 3936 4136 197 >20.4
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of
E(B-V) = 0.075 in the direction of the burst (Schlegel et al. 1998).