GCN Circular 41574
Subject
EP250828a: Einstein Probe detection of an X-ray transient
Event
Date
2025-08-28T10:51:02Z (a month ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
H. Y. Liu (NAO, CAS), K. R. Ni (CCNU) , H. L. Peng (NJNU), Y. J. Song and H. Sun (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 EP250828a. The transient triggered EP-WXT (ID: 01709200900) at 2025-08-28T07:32:33 (UTC). The WXT position of the source is R.A. = 327.905 deg, DEC = 20.567 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) was performed at 2025-08-28T08:48:40 (UTC) . Within the WXT error circle, an uncatalogued X-ray source was detected at R.A. = 327.8966 deg, DEC = 20.5435 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic).
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).