GCN Circular 23358
Subject
GRB 181020A: LCO Cerro Tololo observations
Date
2018-10-21T15:54:44Z (6 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
A. Cucchiara (U. Virgin Islands), C. Guidorzi, R. Martone (U. Ferrara),
S. Kobayashi (LJMU), C.G. Mundell (U. Bath), A. Gomboc (U. Nova Gorica),
I.A. Steele (LJMU), D. Morris (U. of Virgin Islands) on behalf of a
large collaboration report:
We observed Swift GRB 181020A (Moss et al. GCN 23349) with one of the
LCO 1-m unit at Cerro Tololo Observatory on October 20, from 23:55 to
Oct 21, 00:49 UT (corresponding to 4.9 to 5.8 hours from the GRB trigger
time) with the SDSS r' and i' filters. We clearly detect the optical
afterglow (Moss et al. GCN 23349) in both filters with the following
magnitudes for the first half of the observation run:
Mid time from GRB���������� Exposure���������������� Filter������������������ Magnitude
trigger time (hrs)�������� (s)
---------------------------------------------------------------------
5.0������������������������������������ 5x120������������������������ SDSS r'���������������� 17.55 +- 0.03
5.2������������������������������������ 5x120������������������������ SDSS i'���������������� 17.2�� +- 0.1
---------------------------------------------------------------------
as calibrated against nearby USNO UCAC4 objects.