GCN Circular 28799
Subject
GRB 201027A: Swift/UVOT Upper Limits
Date
2020-10-28T14:19:28Z (4 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 201027A 87 s after the BAT trigger
(Cenko et al., GCN Circ. 28788). No optical afterglow consistent with the XRT position (Cenko et al.
GCN Circ. 28788) 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 87 236 147 >20.2
u_FC 299 548 246 >19.5
white 87 1721 411 >21.2
v 629 1771 136 >18.3
b 554 1696 117 >19.3
u 299 1671 343 >20.1
w1 678 1818 135 >19.1
m2 653 1795 78 >20.4
w2 604 1574 117 >20.2
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of
E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).