GCN Circular 27648
Subject
GRB 200424A: Swift/UVOT Upper Limits
Date
2020-04-25T23:20:23Z (4 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the INTEGRAL GRB 200424A
(Mereghetti et al. GCN Circ. 27634) between T0+17 ks and T0+31 ks,
where T0 = 2020-04-24 12:06:45 UT.
We report here the UOT results for source #1 found by the Swift/XRT
(D'Avanzo et al., GCN Circ. 27640).
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(ks) T_stop(ks) Exp(s) Mag
v 18 30 236 >19.1
b 17 30 236 >20.2
u 17 30 236 >19.9
w1 17 30 492 >19.9
m2 17 31 2678 >20.8
w2 17 30 944 >20.4
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).