TITLE: GCN CIRCULAR NUMBER: 44325 SUBJECT: EP260417a: Einstein Probe detection of an X-ray transient DATE: 26/04/17 11:44:47 GMT FROM: EP Team at NAOC/CAS <ep_ta@bao.ac.cn> Y. L. Wang (NAO, CAS; ICE, CSIC), Y. Q. Zhao (USTC; PRIC), K. R. Ni (CCNU) and Z. X. Ling (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of an X-ray transient by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP260417a. The source was detected at 2026-04-17 00:23:02 (UTC). The WXT light curve showed a slow decreasing trend. The WXT position of the source is R.A. = 245.324 deg, DEC = -22.023 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). Preliminary spectral analysis with an absorbed power-law model gave a best-fit photon index of 0.75 (-0.38/+0.97) and an unconstrained hydrogen column density of ~2.3e-20. The unabsorbed 0.5-4 keV flux is 1.3(-0.3/+0.4)e-10 erg/s/cm^2. Quoted uncertainties are at 90% confidence level. A follow-up observation with the Follow-up X-ray Telescope (FXT) on board EP has been scheduled. Further information will be updated when the telemetry data is received. 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/44325. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...