TITLE: GCN CIRCULAR NUMBER: 43730 SUBJECT: EP260213a: refined analysis of the EP-FXT observation DATE: 26/02/14 06:39:43 GMT FROM: EP Team at NAOC/CAS <ep_ta@bao.ac.cn> R.-Z. Li (YNAO, CAS), J. Yang (ZZU), X. Tian (GXU), W. D. Zhang (NAOC) on behalf of the Einstein Probe (EP) team: The fast X-ray transient EP260213a triggered the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission (Yang et al., GCN 43729), and was followed by NOT (Cotter et al., GCN 43728). The autonomous observation by the Follow-up X-ray Telescope (FXT) was performed at 2026-02-13T20:03:06 (UTC), about 5 minutes after T0. The effective exposure time of this observation is around 4.7 ks. The on-ground analysis shows that an uncatalogued source was detected at R.A. = 167.0070, DEC = 3.9470 (J2000) with an uncertainty of 10 arcsec in radius (90% C.L. statistical and systematic). The average 0.5-10 keV spectrum can be fitted with an absorbed power law with a fixed Galactic hydrogen column density of 5.60 × 10^20 cm^-2 and a photon index of 2.18 (-0.15/+0.16). The derived average unabsorbed 0.5-10 keV flux is 1.77 (-0.17/+0.19) × 10^(-12) erg/cm^2/s. The uncertainties are at the 90% confidence level for the above parameters. Further FXT follow-up observations have been arranged. 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/43730. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...