GCN Circular 23283
Subject
GRB 180930A: Swift/UVOT Upper Limits
Date
2018-09-30T20:40:45Z (6 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and A. Tohuvavohu (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180930A
212 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 23279).
No optical afterglow consistent with the XRT position
(Evans GCN Circ. 23280)
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) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 212 362 147 >21.2
white 212 2818 602 >21.1
v 517 2620 226 >20.1
b 443 2718 240 >20.7
u 418 2693 245 >19.7
w1 394 2669 253 >20.8
m2 369 2644 233 >19.3
w2 659 2595 194 >19.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).