TITLE:   GCN CIRCULAR
NUMBER:  23777
SUBJECT: GRB 190123A: GMG observational limit
DATE:    19/01/24 05:53:15 GMT
FROM:    Jirong Mao at Yunnan Obs  <jirongmao_obs@ynao.ac.cn>

J. Mao, L.-F. Xing, M. Xiao, J.-M. Bai (YNAO) report: 


We observed the field of GRB 190123A (D'Ai et al. GCN Circ. 23769) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. The observation began at UT 13:15:51, 23, Jan, 2019, about 1 hour after the trigger. We did not detect any source within the Swift-XRT error circle down to a magnitude of R~22.7.