GCN Circular 20508
Subject
GRB 170121B: LCO FTN observations
Date
2017-01-23T08:41:54Z (8 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), S. Kobayashi, I.A. Steele (LJMU), A. Gomboc
(U. Nova Gorica), C.G. Mundell (U. Bath) on behalf of a large
collaboration report:
We observed Fermi GRB 170121B (Hamburg et al. GCN 20505) on January 23,
07:21 UT (1.7 days since the GRB) with the 2-m LCO Faulkes Telescope
North in Hawaii with SDSS r and i filters. We do not detect the MASTER
optical counterpart (Lipunov et al. GCN 20502) down to the following limits:
Mid Time Exposure Filter Magnitude (AB)
(days) (s)
-------------------------------------------------------
1.69 2x120 SDSS-R > 21.0
1.69 2x120 SDSS-I > 19.5
-------------------------------------------------------
as calibrated against nearby USNO-URAT1 sources.