TITLE: GCN CIRCULAR NUMBER: 35795 SUBJECT: Transient EPW20240219aa: Xinglong-2.16m optical upper limit DATE: 24/02/26 01:26:37 GMT FROM: Dong Xu at NAOC/CAS <dxu@nao.cas.cn> Dong Xu, Junjie Jin, Min He, Zhou Fan, Zipei Zhu, Shuaiqing Jiang, Shaoyu Fu, Xing Liu, Jie An, Tianhua Lu, Feng Xiao, Yinan Zhu, Jie Zheng (NAOC) report on behalf of a large collaboration: We observed the field of the X-ray transient and likely gamma-ray burst EPW20240219aa detected by EP (Zhang et al., ATel 16463; Zhang, ATel 16472), Fermi (Zhang et al., GCN 35773; Fletcher et al., GCN 35776), Swift (DeLaunay et al., GCN 35784), and Insight-HXMT (Cai et al., GCN 35785), using the 2.16-m telescope located at Xinglong, Hebei, China. We obtained 9 x 200 s frames in R-band, starting at 13:59:48 UT on 2024-02-22, i.e., 3.33 days after the EP trigger. No new optical transient is identified within the EP/WXT error circle (Zhang et al., ATel 16463) down to a limiting magnitude of R ~ 21.3 mag (AB), using either cross-math or image subtraction against the PanSTAR survey of this field. View this GCN Circular online at https://gcn.nasa.gov/circulars/35795. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...