GCN Circular 23618
J. Mao, Y.-X. Xin, Y. Li, and J.-M. Bai (YNAO) report: We observed the field of GRB 190106A (Sonbas et al., GCN 23615) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. Observations began about 0.5 hours after the trigger. We clearlydetected the optical source reported by Yurkov et al. (GCN 23614). The spectral observation is ongoing.