GCN Circular 44027
Subject
The EP-WXT trigger 00199258890 (EP260316a): a correction to the trigger time and FXT automatic follow-up
Event
Date
2026-03-16T14:23:30Z (3 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
S. Q. Jiang (NAO, CAS), B. Zhang, J. P. Feng (USTC), W. D. Zhang (NAO, CAS) on behalf of the Einstein Probe (EP) team:
The trigger time reported in the notice for EP-WXT alert 00199258890 is incorrect. The correct trigger time is 2026-03-16T12:33:13.451 (UTC), rather than 2026-03-16T20:33:13.451 (UTC).
The X-ray transient was detected by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP260316a. The transient triggered EP-WXT (ID: 00199258890) at 2026-03-16T12:33:13.451 (UTC). The WXT position of the source is R.A. = 226.983 deg, DEC = 27.466 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. = 226.9840 deg, DEC = 27.4447 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).