GCN Circular 20534
Subject
GRB 170126A: Swift/UVOT Detection of a Fading Afterglow
Date
2017-01-26T22:12:19Z (7 years ago)
From
Frank Marshall at GSFC <femarsha@khamseen.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) and D. Kocevski (NASA/MSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170126A
91 s after the BAT trigger (Kocevski et al., GCN Circ. 20530).
A fading source consistent with the enhanced XRT position
(Beardmore et al. GCN Circ. 20531)
is detected in the initial UVOT exposure.
The preliminary UVOT position is:
RA (J2000) = 17:34:31.97 = 263.63319 (deg.)
Dec (J2000) = -64:45:37.3 = -64.76035 (deg.)
with an estimated uncertainty of 0.45 arc sec. (radius, 90% confidence).
Preliminary detection 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 91 222 129 18.10 +/- 0.05
white 11432 12036 590 >19.7
v 1907 2273 58 >17.7
b 1832 6164 132 >20.1
u 1807 6084 255 >19.3
w1 1783 5879 255 >19.8
m2 1931 2297 58 >20.0
w2 1882 2248 58 >19.4
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.10 in the direction of the burst
(Schlegel et al. 1998).