GCN Circular 23499
Subject
GRB 181201A: Swift/UVOT Detection
Event
Date
2018-12-04T00:22:12Z (7 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and J. K. Cannizzo (NASA/UMBC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 18201A
14.3 ks after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 23469).
We confirm the optical afterglow initially reported by MASTER (Podeta et al.,
GCN Circ. 23470, Kong, GCN Circ. 23475, Volnova et al., GCN Circ. 23477, Mazaeva
et al., GCN Circ. 23479, Watson et al., GCN Circ. 23481, Belkin et al., GCN Circ.
23485, Bolmer and Schady, GCN Circ. 23486, Cai et al., GCN Circ. 23491). The
position of the afterglow is also consistent with the XRT afterglow
(Page et al., GCN Circ. 23474). The detection of the afterglow in the uvw2
filter would be consistent with the redshift report by Izzy et al. (GCN Circ. 23488).
The preliminary UVOT position is:
RA (J2000) = 21:17:11.17 = 319.29656 (deg.)
Dec (J2000) = -12:37:51.0 = -12.63084 (deg.)
with an estimated uncertainty of 0.2 arc sec. (radius, 90% confidence).
Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are:
Filter T_start(s) T_stop(s) Exp(s) Mag
uvw2 14310 26435 4901 15.39 +/- 0.02
white 56416 74104 924 17.53 +/- 0.03
white 148341 165117 1162 18.71 +/- 0.04
v 56713 74204 535 17.70 +/- 0.10
v 160066 165389 389 18.70 +/- 0.26
u 56120 77881 2757 17.25 +/- 0.03
u 148114 164276 2896 18.30 +/- 0.05
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).