GCN Circular 36197
Subject
GRB 240419B: Swift/UVOT Upper Limits
Date
2024-04-20T15:20:59Z (13 days ago)
From
Sam Shilling at Lancaster University <shilling.sam@gmail.com>
Via
Web form
S. P. R. Shilling (Lancaster U.), S. R. Oates (Lancaster U.),
A. A. Breeveld (UCL-MSSL), N. P. M. Kuin (UCL-MSSL) and S. Dichiara (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240419B
159 s after the BAT trigger (Dichiara et al., GCN Circ. 36180).
No optical afterglow consistent with either the enhanced XRT position
(Osborne et al., GCN Circ. 36186) or the NOT optical afterglow position
(Malesani et al., GCN Circ. 36191) is detected in the initial UVOT exposures.
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) exposures and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 159 308 147 >20.3
u_FC 317 567 246 >19.5
white 159 790 186 >20.4
v 647 667 19 >17.3
b 572 765 39 >18.6
u 317 741 265 >19.5
w1 696 716 19 >17.5
m2 672 691 19 >17.2
w2 623 643 19 >17.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.077 in the direction of the burst
(Schlegel et al. 1998).