GCN 43828: EP260224a: Einstein Probe detection of an X-ray transient

2026-02-25T09:01:39.294Z | rev 0 | event: EP260224a

Guojiong Yang(NAO, CAS), Jiaying Cao(IHEP), Wenfeng Wen(SZTU) and Haiwu Pan (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 EP260224a. The transient triggered EP-WXT at 2026-02-24T17:03:42 (UTC). The WXT position of the source is R.A. = 175.200 deg, DEC = -41.415 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic).

A follow-up observation with the Follow-up X-ray Telescope (FXT) started at 2026-02-25T06:21:59 (UTC), approximately 13 hours after the WXT trigger. No onboard alert was generated by FXT during this observation.

Further follow-up observations are encouraged.

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).