GCN Circular 31351
Subject
GRB 220101: Swift/UVOT Detection
Date
2022-01-01T14:09:07Z (3 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and A. Tohuvavohu (U Toronto)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220101
90 s after the BAT trigger ( Tohuvavohu et al., GCN Circ. 31347).
A rapidly decayig source consistent with the XRT position
(Osborne et al., GCN Circ. 31349) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 00:05:24.80 = 1.35334 (deg.)
Dec (J2000) = +31:46:08.4 = 31.76899 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric
system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures
are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 90 240 147 14.68 +/- 0.02
v 4448 4647 197 18.70 +/- 0.18
b 3833 4032 197 >19.8
u 3628 5201 334 >20.1
w1 4858 5057 197 >20.1
m2 4652 4852 197 >20.2
w2 4243 4443 197 >20.4
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.056 in the direction of the burst
(Schlegel et al. 1998).