TITLE: GCN CIRCULAR NUMBER: 38759 SUBJECT: GRB 250101A: Xinglong-2.16m spectroscopic redshift DATE: 25/01/01 16:33:10 GMT FROM: Dong Xu at NAOC/CAS <dxu@nao.cas.cn> Z.P. Zhu, S.Y. Fu, X. Liu, S.Q. Jiang, J. An, D. Xu (NAOC) report on behalf of a large collaboration: We carried out spectroscopy of the optical counterpart (e.g., Page et. al., GCN 38752; Li et al., GCN 38753; Mohan et al., GCN 38754; Zhu et al., GCN 38755) of GRB 250101A detected by Swift/BAT (Page et. al., GCN 38752), using the 2.16-m telescope located at Xinglong, Hebei, China. Our spectra cover the wavelength range 3800 - 9000 AA, and consist of 3 exposures of 1800 s each. The whole spectrum has a fairly low S/N, but absorption features are evident. From the detection of a Lya absorption feature at ~ 4240 AA and multiple absorption features, which interpreted as being due to Si II, O I, C IV, Fe II, and Cr II, we infer a common redshift of z = 2.49. We conclude this is the likely redshift of the burst. We acknowledge the expert support from the Xinglong-2.16m staff, in particular Yu Zhang, Junjun Jia, and Jie Zheng. View this GCN Circular online at https://gcn.nasa.gov/circulars/38759. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...