GCN Circular 45261
Subject
EP260731a: Einstein Probe detection of an X-ray transient
Event
Date
2026-07-31T02:15:53Z (a day ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
K.R. Ni (CCNU) , Y.F. Liang (PMO, CAS), H.Y. Liu, and H.W. 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 EP260731a. The transient triggered EP-WXT (ID: 01709277303) at 2026-07-31T00:54:24 (UTC). The WXT position of the source is R.A. = 344.424 deg, DEC = -11.764 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. = 344.4279 deg, DEC = -11.7623 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).