TITLE: GCN CIRCULAR NUMBER: 35390 SUBJECT: GRB 231216A: AST3-3 YaoAn Optical Upper Limit DATE: 23/12/17 15:05:33 GMT FROM: Tianrui Sun at Purple Mountain Obs,CAS <trsun@pmo.ac.cn> Tian-Rui Sun (Purple Mountain Observatory), Yan-Long Hua, Mao-Kai Hu, Xue-Feng Wu, Lei Liu, Ke-Lai Meng, Xiao-Yan Li (Nanjing Institute of Astronomical Observation Technology), Xiang-Yan Yuan, Lifan Wang (TAMU), Xiao-Feng Wang (Tsinghua University), Lei Hu (CMU) report on behalf the AST3 Team: Following the detection of GRB 231216A by Swift (Sbarrato et al., GCNC 35378), we use Antarctic Survey Telescope 3-3 at YaoAn Astronomy Observation Station (China, Yunnan) for follow-up. Our observation started on 2023-12-16T18:44:08 (about 506 seconds after the trigger of BAT (Sbarrato et al., GCNC 35378)). No optical source was detected within the XRT error box down to 20.7 mag in the coadded image (total 600s, g-band). Our non-detection is consistent with the results from the UVOT (Sbarrato et al., GCN 35378), MASTER (Lipunov et al. GCN 35379), the BOOTES-2/TELMA (Hu et al. GCN 35381), NOT (Daniele B. Malesani et al., GCN 35382) and the T120 at Observatoire de Haute-Provence (Basa et al., GCN 35384)limits. We thank the staff at YaoAn Astronomy Observation Station for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/35390. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...