TITLE:   GCN CIRCULAR
NUMBER:  46142
SUBJECT: EP261103a: Einstein Probe detection of an X-ray transient
DATE:    26/11/04 03:27:34 GMT
FROM:    EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

H. Y. Ren (NAO, CAS), B. T. Wang, M. Nie (YNAO, CAS),L.-N. Xu (USTC),X. Tian, S. X. Ren(GXU) 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 EP261103a. The transient triggered EP-WXT (ID: 01709322209) at 2026-11-03T20:18:26 (UTC). The WXT position of the source is R.A. = 81.849 deg, DEC = -25.330 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. = 81.8516 deg, DEC = -25.3269 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).