GCN Circular 22144
Subject
GRB 171120A: Swift/UVOT Upper Limits
Date
2017-11-21T21:21:20Z (6 years ago)
From
Jeffrey Gropp at PSU <jdg44@psu.edu>
J. D. Gropp (PSU) and A. Tohuvavohu (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171120A
99 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22133).
No optical afterglow consistent with the refined XRT position
(Evans et al. GCN Circ. 22135)
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 99 249 147 >19.9
u_FC 311 561 246 >19.7
white 99 5989 560 >21.1
v 640 6399 413 >19.1
b 566 5784 413 >20.9
u 311 11713 811 >20.7
w1 5174 11532 1082 >21.0
m2 9724 10624 886 >21.0
w2 4559 6194 393 >21.0
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).