TITLE: GCN CIRCULAR NUMBER: 42573 SUBJECT: GRB 251103A: Xinglong 2.16m optical detection DATE: 25/11/04 11:27:31 GMT FROM: Youdong HU at GXU <huyoudong072@hotmail.com> L. P. Xin (NAOC), Y.-D. Hu, X. Tian (GXU), Y. Zhang, J. Wang, J.-Y. Wei (NAOC) report on behalf of SVOM follow-up team: We observed the field of GRB 251103A (Hu et al., GCN 42534; Fermi GBM Team, GCN 42536; Wang et al., GCN 42552; Sonawane et al., GCN 42553; DeLaunay et al., GCN 42568; Ren et al., GCN 42572). using the 2.16-m telescope located at Xinglong observatory, China, equipped with the BFOSC camera. We obtained 9*200s frames in R-band, starting at 21:11:22 UT on 2025-11-03, about 16.7 hrs after the trigger. The optical afterglow (Schneider et al., GCN 42535; Turpin et al., GCN 42538; Gritsevich et al., GCN 42539; Izzo et al., GCN 42540; O'Neill et al., GCN 42543; Ghosh et al., GCN 42545; Schneider et al., GCN 42549; Breeveld et al., GCN 42554; Hellot et al., GCN 42559; Mo et al., GCN 42562; Zheng et al., GCN 42571) was clearly detected in the stacked image with a magnitude of R=20.78+-0.08 mag at the mid time, which calibrate with nearby SDSS stars. We thank the staff at Xinglong observatory for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/42573. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...