GCN Circular 27709
Subject
GRB 200509A: Swift/UVOT Detection
Date
2020-05-10T00:34:40Z (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 200509A
123 s after the BAT trigger (Troja et al., GCN Circ. 27701). A source
consistent with the XRT position (Troja et al. GCN Circ. 27701) is
detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 07:45:41.28 = 116.42200 (deg.)
Dec (J2000) = -04:37:49.3 = -4.63035 (deg.)
with an estimated uncertainty of 0.48 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 123 273 147 18.92 +/- 0.08
v 611 1738 122 >18.6
b 537 1678 117 >19.8
u 281 531 246 18.46 +/- 0.10
w1 660 1628 117 >19.0
m2 636 1604 117 >19.0
w2 587 1728 136 >19.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.13 in the direction of the burst
(Schlegel et al. 1998).