GCN Circular 22059
Subject
GRB 171027A: LCO 1-m telescope observations
Date
2017-10-27T11:51:22Z (7 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath),
A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large
collaboration report:
We began observing Swift GRB171027A (D'Avanzo et al. GCN 22053) on
October 27, from 08:39:29 to 09:06:37 UT (16 minutes since the GRB
trigger time) with one of the 1-m LCO McDonald telescopes in the SDSS
gri filters. Within the enhanced Swift-XRT error circle (Evans et al.
22054) and in particular at the position of the NIR afterglow candidate
(Watson et al. GCN 22057) we do not see any optical source down to the
following limits in agreement with previous reports (Lipunov et al. GCN
22055; Schady et al. GCN 22056):
Mid Time���� Exposure������ Filter������ Magnitude (AB)
(hrs)�������� (s)
-------------------------------------------------------
0.5��������� 5x60���������� SDSS-G��������� > 19.5
0.5��������� 5x60���������� SDSS-R��������� > 19.3
0.5��������� 5x60���������� SDSS-I��������� > 18.8
-------------------------------------------------------
as calibrated against nearby USNO URAT1 objects.