GCN Circular 35534
Subject
GRB 240112C: Swift/UVOT Detection
Date
2024-01-14T18:22:22Z (a year ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Via
email
N. P. M. Kuin (UCL-MSSL) and Eyles-Ferris (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240112C
121 s after the BAT trigger (Eyles-Ferris et al., GCN Circ. 35522).
A source consistent with the XRT position is detected in the initial
UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 18:02:34.58 = 270.64410 (deg.)
Dec (J2000) = +24:29:21.3 = 24.48925 (deg.)
with an estimated uncertainty of 0.43 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 121 236 113 16.98 +/- 0.04
v 4955 5126 169 >18.6
b 4340 4539 197 19.35 +/- 0.16
u 4134 4334 197 19.11 +/- 0.18
w1 3930 4129 197 19.13 +/- 0.24
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.108 in the direction of the burst
(Schlegel et al. 1998).