GCN Circular 32727
J. Mao, K.-X. Lu, X.-H. Zhao, and J.-M. Bai (YNAO) report: We observed the field of GRB 221009A (Dichiara et al. GCN 32632) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. The observation began at UT 14:34:40, 12, Oct. 2022, about 3 days after the trigger. We marginally detected the afterglow. The preliminary magnitude was measured to be z~18.9. We caution that the magnitude has a relatively large uncertainty due to the very poor seeing.