TITLE: GCN CIRCULAR NUMBER: 42801 SUBJECT: GRB 251122A/EP251122a: SVOM/C-GFT upper limit DATE: 25/11/22 16:06:03 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC), Yulei Qiu(NAOC), Jing Wang (NAOC), Jinsong Deng(NAOC), Lei Huang(NAOC), Jianyan Wei (NAOC), Z.-Y. Lin, C. Lachaud (APC) report on behalf of the SVOM/C-GFT team: We observed the field of GRB 251122A detected by EP/WXT(Wang et al., GCN 42799, ID:01709248658) and SVOM/ECLAIRs (Lin et al., GCN 42800, SVOM burst-id sb25112204) with LATIOS on SVOM/C-GFT. Observations started at 2025-11-22T13:59:06 UTC, ~118 seconds after the trigger. A series of g, r, and i band images were obtained. No credible candidate was detected within the error box provided by EP/FXT (Wang et al., GCN 42799) and SVOM/MXT (Lin et al., GCN 42800 ) in our images after preliminary processing, the three sigma upper limit is: | Date-Obs (mid-time) | Mid_t - T0 (s) | Exposure Time (s) | Band | Upper Limit (AB) | |---------------------|----------------|-------------------|------|------------------| | 2025-11-22T13:59:45 | 157 | 6×10 | i | 20.05 | The photometry was calibrated against nearby UCAC4 catalogue and no correction for Galactic dust extinction was applied. We thank the observation assistants Bowen Li and Hongyan Xue at Jilin observatory for their excellent support. The Chinese Ground Follow-up Telescope (C-GFT) for the SVOM mission is located at Jilin Station, Changchun Observatory, National Astronomical Observatories, CAS. It features two instruments: (1) CATCH at the Cassegrain focus with a 21 arcsec x 21 arcsec FOV for simultaneous g/r/i-band imaging, and (2) LATIOS, a 4k x 4k CMOS camera at the prime focus with a 1.28 deg x 1.28 deg FOV that images in g, r, and i bands via filter switching. View this GCN Circular online at https://gcn.nasa.gov/circulars/42801. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...