{
  "submittedHow": "web",
  "eventType": [
    "X-ray Transient"
  ],
  "subject": "EP260901a: EP-WXT detection of a fast X-ray transient",
  "format": "text/plain",
  "body": "Y. F. Liang, J. Y. Liu (PMO), X. Mao, Q. H. Lao, Z. X. Ling (NAO, CAS) on behalf of the Einstein Probe (EP) team:\n\nWe report on the detection of a fast X-ray transient, designated EP260901a (notice ID: 11900871682), by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The transient was identified in the telemetry data. The transient started about 2026-09-01T05:07:45(UTC) and lasted for about 500s. The position of the transient is R.A. = 260.845 deg, Dec. = -19.232 (J2000), with an uncertainty radius of 2.4 arcmin in radius (90% confidence level, including both statistical and systematic uncertainties). There are no known X-ray sources in the WXT error circle.\n\nThe average WXT 0.5-4 keV spectrum can be fitted by an absorbed power-law model with a fixed Galactic hydrogen column density of 3.34 × 10^21 cm^-2 and a photon index of 1.12 (-0.07/+0.07). The derived average unabsorbed 0.5-4 keV flux is 3.96(-0.61/+0.68) x 10^(-10) erg cm^-2 s^-1. The peak flux is about 3.7 x 10^(-9) erg cm^-2 s^-1. The uncertainties are at the 90% confidence level for the above parameters.\n\nFollow-up observations by EP-FXT will be arranged.\n\nLaunched on 2024 January 9, Einstein Probe is a space-based X-ray observatory designed to monitor the dynamic X-ray sky and perform rapid follow-up observations of newly discovered transients (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).",
  "eventId": "EP260901a",
  "submitter": "EP Team at NAOC/CAS <ep_ta@bao.ac.cn>",
  "createdOn": 1788268591233,
  "circularId": 45487
}