GCN Circular 28482
Subject
GRB 200922A: Swift/UVOT Detection
Event
Date
2020-09-23T13:04:40Z (5 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and M. J. Moss (GWU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 200922A
86 s after the BAT trigger (Moss et al., GCN Circ. 28471).
We identify a fading source near the XRT position
(Osborne et al. GCN Circ. 28473) and also at the location of a weak source
in the DSS. The source position is:
RA(J2000) = 19:47:48.76 = 296.95317
DEC(J2000) = -55:12:16.5 = -55.20457
Which is 3.0 arc-second from the enhanced XRT position.
Preliminary detections 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 86 236 147 14.37+/-0.02
white 4770 4970 196 17.51+/-0.04
white 28889 28909 19 18.62+/-0.20
v 3745 3945 196 17.35+/-0.10
v 9268 23149 1460 17.79+/-0.05
b 4566 4765 196 17.95+/-0.07
b 27982 28889 881 18.49+/-0.05
u 4360 4560 196 17.18+/-0.06
u 15921 16791 848 18.20+/-0.06
uvw1 4156 4355 196 17.23+/-0.10
uvw1 11089 15915 887 18.26+/-0.09
uvw1 50455 56029 225 18.97+/-0.27
uvm2 3950 4150 196 17.12+/-0.12
uvm2 10182 11081 885 18.19+/-0.10
uvm2 50396 55850 223 19.26+/-0.36
uvw2 3541 5089 307 17.14+/-0.09
uvw2 21653 22553 885 18.77+/-0.12
uvw2 50338 55672 223 >19.44
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).