GCN Circular 23719
Subject
GRB 190114A: Swift/UVOT Observations
Date
2019-01-15T16:52:55Z (5 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and S. J. LaPorte (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 190114A
258 s after the BAT trigger (LaPorte et al., GCN Circ. 23677).
We confirm a source consistent with the XRT position (Evans et al. GCN
Circ. 23681) as initially reported in UVOT (Siegel \& LaPorte, GCN Circ. 23678)
and later detected by GROND (Bolmer \& Schady, GCN Circ. 23682), OSN (de Ugarte
Postigo et al., GCN Circ. 23687) and NOT (Selsing et al., GCN Circ. 23697).
Notably, the optical counterpart was not seen in the initial finding chart and
had faded beyond detectability by the second orbit. The lack of detection in any
of the NUV filters would be consistent with the redshift of 3.4 reported by
de Ugarte Postigo et al. (GCN Circ. 23680).
The preliminary UVOT position is:
RA (J2000) = 04:22:10.55 = 65.54397 (deg.)
Dec (J2000) = +02:11:29.6 = 2.19157 (deg.)
with an estimated uncertainty of 0.42 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 (fc) 258 408 147 >20.58
white 514 1701 264 19.69+/-0.13
v 564 1752 136 18.33+/-0.22
b 490 1676 136 19.57+/-0.27
u 465 1825 155 >19.64
uvw1 440 1801 155 >19.17
uvm2 5866 7502 393 >19.66
uvw2 540 1726 136 >19.12
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.22 in the direction of the burst
(Schlegel et al. 1998).