GCN Circular 22040
Subject
GRB 171020A: Swift/UVOT Upper Limits
Event
Date
2017-10-22T06:43:09Z (8 years ago)
From
Sam LaPorte at PSU <sjl5346@psu.edu>
GRB 171020A: Swift/UVOT Upper Limits
S. J. LaPorte (PSU) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171020A
147 s after the BAT trigger (Page et al., GCN Circ. 22028).
No optical afterglow consistent with the XRT position
(Page et al. GCN Circ. 22028)
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 147 297 147 >20.6
u_FC 306 556 246 >20.2
white 147 7652 811 >21.4
v 636 6640 338 >19.4
b 562 7460 529 >20.8
u 306 7254 756 >20.2
w1 686 7050 491 >20.7
m2 6645 6845 197 >20.3
w2 1016 6435 216 >20.3
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.19 in the direction of the burst
(Schlegel et al. 1998).