GCN Circular 35135
Subject
231118A: Swift-UVOT Detection
Date
2023-11-20T12:42:03Z (2 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Via
legacy email
N.P.M. Kuin (MSSL/UCL) and S. L. Laha (GSFC/UMBC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 231118A
105 s after the BAT trigger (Laha et al., GCN Circ. 35101).
A source consistent with the XRT position (Evans et al., GCN Circ. 35106)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 00:19:19.26 = 4.83024 (deg.)
Dec (J2000) = -48:02:24.1 = -48.04004 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections 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 105 255 147 17.28 +/- 0.03
v 1052 1071 20 16.59 +/- 0.16
b 573 593 19 17.10 +/- 0.11
u 318 568 246 16.69 +/- 0.04
w1 1618 1638 19 17.18 +/- 0.24
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.013 in the direction of the burst
(Schlegel et al. 1998).