TITLE: GCN CIRCULAR NUMBER: 42841 SUBJECT: EP251124b follow-up observation by EP-FXT DATE: 25/11/26 10:26:21 GMT FROM: EP Team at NAOC/CAS <ep_ta@bao.ac.cn> B. Zhang, J. P. Feng (USTC), D. F. Hu (PMO, CAS), H. Sun, H. N. Yang (NAO, CAS), Z. C. Zou (NJU) on behalf of the Einstein Probe (EP) team: We performed a Target-of-Opportunity observation with the Follow-up X-ray Telescope on board the Einstein Probe (EP) for EP251124b (Feng et al, GCN 42834), which was also followed by Lipunov et al. (GCN #42835) and van Hoof et al. (GCN #42839). The observation began at 2025-11-25T22:12:00 (UTC) with an exposure time of about 1790 seconds. An uncatalogued X-ray source was detected within the WXT error circle at R.A. = 93.4802 deg, DEC = 52.7313 deg (J2000) with an uncertainty of 10 arcsec in radius (90% C.L. including both statistical and systematic uncertainties). The average FXT 0.5-10 keV spectrum can be fitted with an absorbed power law with a fixed Galactic hydrogen column density of 1.5 x 10^21 cm^-2 and a photon index of 0.97 (-0.84, +0.93). The derived average unabsorbed 0.5-10 keV flux is 9.02 (-5.33, +13.9) x 10^(-13) erg/s/cm^2. 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/42841. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...