GCN Circular 44240
Subject
EP260409a: Einstein Probe detection of an X-ray transient
Event
Date
2026-04-09T01:55:16Z (6 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
S. Q. Jiang (NAO, CAS), G. L. Huang, Z. X. Li, J. Y. Cao (IHEP, CAS), W. D. Zhang (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 EP260409a. The transient triggered EP-WXT (ID: 01709259735) at 2026-04-09T00:18:21 (UTC). The WXT position of the source is R.A. = 172.895 deg, DEC = -9.348 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 circle, an uncatalogued X-ray source was detected at R.A. = 172.9080 deg, DEC = -9.3442 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).