GCN Circular 26002
Subject
GRB 191011A: Swift/UVOT Detection
Event
Date
2019-10-11T17:23:17Z (6 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and Laha (GSFC/UMBC/CRESST)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 191011A
78 s after the BAT trigger (Laha et al., GCN Circ. 25988). A source
consistent with the XRT position (Evans et al. GCN Circ. 25995)
is detected in the initial UVOT exposures. This GRB was also detected
by Fermi/GBM (GCN Circ. 25987,26000) and Insight-HXMT-HE(Yi et al, GCN
Cir. 25997). A redshift was reported using the VLT/Xshooter (Kahn et al,
GCN Circ.25991), while the optical afterglow was reported from Master
(Lipunov et al, GCN Circ. 25990; GROND (Nicuesa Guelbenzu et al.,
GCN Circ. 25992).
The preliminary UVOT position is:
RA (J2000) = 02:58:54.79 = 44.72829 (deg.)
Dec (J2000) = -27:50:43.4 = -27.84540 (deg.)
with an estimated uncertainty of 0.73 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 78 228 147 20.27 +/- 0.16
v 620 11672 1211 >20.2
b 545 7080 510 21.03 +/- 0.27
u 290 6875 697 20.86 +/- 0.27
w1 670 6670 510 >20.3
m2 1073 12198 767 >21.1
w2 1024 7491 432 >20.9
The afterglow is seen to be nearly constant in the white filter until
about 1000s, whereafter a decay is observed. The magnitudes in the table
are
not corrected for the Galactic extinction due to the reddening of E(B-V) =
0.02
in the direction of the burst (Schlegel et al. 1998).