GCN Circular 23505
Subject
GRB 181203A: Swift/UVOT Upper Limits
Date
2018-12-04T16:55:56Z (5 years ago)
From
Frank Marshall at Swift/UVOT <marshall@milkyway.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) 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 181203A
79 s after the BAT trigger (Troja et al., GCN Circ. 23493).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 23494)
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 79 229 147 >20.7
u_FC 293 543 246 >19.4
white 79 1370 373 >21.8
v 624 1421 97 >18.6
b 549 1346 78 >20.0
u 293 1495 324 >19.7
w1 673 1470 97 >19.0
m2 648 1445 97 >18.5
w2 599 1396 97 >19.7
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.24 in the direction of the burst
(Schlegel et al. 1998).