TITLE: GCN CIRCULAR NUMBER: 42809 SUBJECT: GRB 251122A / EP251122a: EP-FXT counterpart detection DATE: 25/11/23 03:57:25 GMT FROM: EP Team at NAOC/CAS <ep_ta@bao.ac.cn> B.-T. Wang (YNAO), Y.-H. I. Yin (HKU), G. J. Yang (NAOC), H.-Z. Wu (HUST) and W. D. Zhang (NAOC) on behalf of the Einstein Probe (EP) team: EP-FXT performed a follow-up observation of the SVOM/ECLAIRs-detected burst GRB 251122A (SVOM/sb25112204, Lin et al., GCN 42800), also triggered by EP/WXT as EP251122a (Wang et al., GCN 42799) at 2025-11-22T17:08:09 (UTC), about 3.2 hours after the SVOM/ECLAIRs trigger, with an exposure time of 1719 s. One uncatalogued source is detected within the ECLAIRs error circle, and the source is spatially consistent with the counterpart reported in optical and X-ray bands, including detections (Cheng et al., GCN 42803; Li et al., GCN 42806; Sun et al., GCN 42807; Yin et al., GCN 42808) and several upper limits (Wu et al., GCN 42801; Lipunov et al., GCN 42802; Saccardi et al., GCN 42804; Cotter et al., GCN 42805). Preliminary analysis on this source are automatically conducted, and details are listed as follows. Source 1: EPF_J023205.2+140740 RA (J2000): 38.0226 Dec (J2000): 14.1282 Flux: 5.27 x 10^-13 erg/s/cm2 (observed, 0.5-10 keV) Flux_err: 1.04 x 10^-13 erg/s/cm2 (1 sigma) The position uncertainty of the source is about 10 arcsec in radius (90% C.L. statistical and systematic). Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/42809. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...