GCN Circular 39429
Subject
EP250223a: Einstein Probe detection of an X-ray transient
Date
2025-02-23T16:22:43Z (14 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
T. Y. Lian, W. J. Zhang (NAOC, CAS), Y. Wang (PMO, CAS), X. Tian (GXU), R. Z. Li(YNAO, CAS), H. W. Pan (NAOC, CAS) report on behalf of the Einstein Probe 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 EP250223a. The transient triggered EP-WXT (ID: 01709131863) at 2025-02-23T15:04:35.749 (UTC). The WXT position of the source is R.A. = 98.258 deg, DEC = -22.432 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 automatically. Within the WXT error cirlce, an uncatalogued X-ray source was detected at R.A. = 98.2722 deg, DEC = -22.4442 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).