TITLE: GCN CIRCULAR NUMBER: 44641 SUBJECT: EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations DATE: 26/05/16 08:08:24 GMT FROM: EP Team at NAOC/CAS <ep_ta@bao.ac.cn> Y.-H. Cheng (SWIFAR, YNU), K.R. Ni (CCNU), R.-Z. Li (YNAO, CAS) and W.-D. Zhang (NAO, CAS) on behalf of the Einstein Probe (EP) team: The X-ray transient EP260514a was detected by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission (Cheng et al., GCN 44613) at 2026-05-14T16:56:06 (UTC). The average WXT 0.5-4 keV spectrum can be fitted with an absorbed power law with a fixed Galactic hydrogen column density of 1.49 × 10^20 cm^-2, and a photon index of 1.32 (+/-0.22). The derived average unabsorbed 0.5-4 keV flux is 4.24 (+0.70/-0.60) × 10^(-10) erg/s/cm^2. Follow-up observation by the Follow-up X-ray Telescope (FXT) on board EP was performed at 2026-05-15 08:20:00(UTC), ~15.5 hours after the WXT detection. The exposure time of the observation is around 5 ks. The on-ground analysis of the FXT data found an uncatalogued source at R.A. = 214.2955 deg, DEC = 49.3733 deg (J2000) with an uncertainty of 10 arcsec (radius, 90% C.L. statistical and systematic). The average FXT 0.5-10 keV spectra can be fitted with an absorbed power-law with a fixed hydrogen column density of 1.49 × 10^20 cm^-2 and a photon index of 1.28 (+0.76/-0.67). The derived average unabsorbed 0.5-10 keV flux is 2.28 (-0.55/+1.17) × 10^(-13) erg/s/cm^2. The uncertainties are at the 90% confidence level for the above parameters. The optical observations of EP260514a were reported by Lipunov et al. (GCN 44614), Mohan et al. (GCN 44619), Sánchez et al. (GCN 44632) and Li et al. (GCN 44638), Liu et al.,(GCN 44639) and Liu et al.,(GCN 44640). 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/44641. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...