GCN Circular 28745
Subject
GRB 201021C: Swift/UVOT Detection
Event
Date
2020-10-22T13:16:47Z (6 years ago)
From
Samantha Oates at MSSL <samantha.oates@alumni.ucl.ac.uk>
S. R. Oates (U.Birmingham) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 201021C
105 s after the BAT trigger (Lien et al., GCN Circ. 28730).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 28736)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 00:50:06.93 = 12.52886 (deg.)
Dec (J2000) = -55:51:56.8 = -55.86577 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
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 (FC) 105 255 147 16.66 +/- 0.03
white 598 617 19 16.22 +/- 0.05
v 647 667 19 16.49 +/- 0.16
b 573 593 20 16.80 +/- 0.10
u (FC) 317 567 246 15.76 +/- 0.03
u 722 742 19 16.06 +/- 0.10
uvm2 672 692 19 16.43 +/- 0.24
uvw2 623 643 19 16.68 +/- 0.22
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).