GCN Circular 26566
A.K.H. Kong (NTHU, Taiwan) reports We observed the field of GRB 191221B (Laha et al., GCN 26534) with the T17 0.43m telescope of iTelescope.Net in Siding Spring, Australia. The observation was done with a SDSS r filter beginning at 2019-12-22 14:56:51 UT (about 18 hours after the trigger) for 300 sec. The optical counterpart (Laha et al., GCN 26534) was detected with r=18.4+/-0.1 (AB) by calibrating with the SkyMapper Southern Sky Survey.