GCN Circular 45362
Subject
EP260812a: Einstein Probe detection of an X-ray transient
Event
Date
2026-08-12T12:00:11Z (2 days ago)
Edited On
2026-08-12T13:07:46Z (2 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
Tian-Yu Liu, H. R. Ren, G. J. Yang 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 EP260812a. The transient triggered EP-WXT (ID: 01709278114) at 2026-08-12T11:21:01 (UTC). The WXT position of the source is R.A. = 311.450 deg, DEC = 14.142 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. = 311.4377 deg, DEC = 14.1600 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).