{
  "circularId": 45253,
  "eventType": [
    "X-ray Transient"
  ],
  "body": "H. Zhou (PMO, CAS), G. J. Yang, J. W. Hu, C. C. Jin (NAO, CAS) on behalf of the Einstein Probe (EP) team:\n\nWe 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 EP260729a. The transient triggered EP-WXT (ID: 01709277130) at 2026-07-29T17:04:47 (UTC). The WXT position of the source is R.A. = 357.559 deg, DEC = 26.992 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic).\n\nA follow-up observation with the Follow-up X-ray Telescope (FXT) was performed automatically. Within the WXT error circle, an uncatalogued X-ray source was detected at R.A. = 357.5308 deg, DEC = 26.9981 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic).\n\nPlease note that an M4.0V C-type star, RX J2350.0+2659 (High Proper Motion Star), exists within the FXT error circle. Due to limited data, we cannot rule out the possibility that WXT was triggered by a stellar flare from RX J2350.0+2659.\n\nFurther information will be updated when the telemetry data is received.\n\nLaunched 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).",
  "editedOn": 1785356840269,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of EP Team at NAOC/CAS <ep_ta@bao.ac.cn>",
  "eventId": "EP260729a",
  "submitter": "EP Team at NAOC/CAS <ep_ta@bao.ac.cn>",
  "submittedHow": "web",
  "version": 3,
  "format": "text/plain",
  "subject": "EP260729a: Einstein Probe detection of an X-ray transient",
  "createdOn": 1785348074752,
  "bibcode": "2026GCN.45253....1Z"
}