GCN Circular 16157
Subject
GRB 140423A: Further Observations with Swift/UVOT
Event
Date
2014-04-23T21:12:24Z (12 years ago)
From
Margaret Chester at PSU <chester@swift.psu.edu>
M. M. Chester (PSU), E. Sonbas (NASA/GSFC/Adiyaman Univ.), and
F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team:
Further analysis confirms UVOT's detection of the afterglow of GRB 140423A
(Sonbas et al., GCN Circ. 16142) reported by Elenin et al. (GCN Circ. 16143).
The UVOT position based on the initial exposure is:
RA (J2000) = 13:09:08.54 = 197.28558 (deg.)
Dec (J2000) = +49:50:29.4 = 49.84150 (deg.)
with an estimated uncertainty of 0.48 arc sec. (radius, 90% confidence).
This position is consistent with the enhanced XRT position reported by
Beardmore et al. (GCN Circ. 16155).
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 2947 3097 147 19.80 +/- 0.09
v 3104 3303 197 19.33 +/- 0.19
b 3924 4123 197 19.96 +/- 0.16
u 3719 5353 393 >21.3
w1 3513 5148 393 >21.7
m2 4743 4943 197 >20.7
w2 4334 11161 808 >22.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).