GCN Circular 16130
Subject
GRB 140419A: Swift UVOT refined analysis
Event
Date
2014-04-19T21:55:33Z (11 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and F. E. Marshall (NASA/GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140419A
97 s after the BAT trigger (Marshall et al. GCN Circ. 16118).
Optical and IR photometry and positions were reported, as well as a redshift
(Cenko, et al., GCN Circ. 16129; Hentunen et al., GCN Circ. 16126; Tanvir
et
al., GCN Circ. 16125; Kuin et al., GCN Circ. 16123; Butler et al., GCN
Circ.
16121; Guver et al., GCN Circ. 16120; and Zheng et al., GCN Circ. 16119.)
A source consistent with the XRT position is detected in the initial UVOT
exposures.
The preliminary UVOT position is:
RA (J2000) = 08:27:57.56 = 126.98982 (deg.)
Dec (J2000) = +46:14:25.3 = 46.24037 (deg.)
with an estimated uncertainty of 0.50 arc sec. (radius, 90% confidence).
Due to the GRB lying on the edge of a large scattered light feature from
the
bright star nearby, photometry errors are large until a good background
template can be made at late times.
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 97 246 147 16.2 +/- 0.2
v 638 658 19 16.1 +/- 0.2
b 564 756 39 18.4 +/- 0.2
u 309 2003 362 >21.0
w1 687 707 19 >18.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).