GCN Circular 29485
Subject
GRB 210211A: Swift/UVOT Detection
Event
Date
2021-02-11T22:59:12Z (5 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210211A
78 s after the BAT trigger (Troja et al., GCN Circ. 29472). A source
consistent with the XRT position (Osborne et al. GCN Circ. 29478) and
the REM detection (d'Avanzo et al., GCN Circ. 29474)is detected in
the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 17:57:45.68 = 269.44035 (deg.)
Dec (J2000) = -46:16:01.6 = -46.26711 (deg.)
with an estimated uncertainty of 0.47 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 78 227 147 17.89 +/- 0.06
white 596 611 15 >18.6
white 5391 5587 197 >20.3
v 4239 4438 197 >19.8
b 545 565 19 >18.4
u 290 489 196 >18.6
m2 4444 4491 47 >18.3
w2 4034 4234 197 >19.4
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.127 in the direction of the burst
(Schlegel et al. 1998).