TITLE:   GCN CIRCULAR
NUMBER:  45828
SUBJECT: EP261007a/GRB 261007A: Einstein Probe detection of an X-ray transient
DATE:    26/10/07 08:56:40 GMT
FROM:    EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

W.F. Wen (SZTU), Q.H. Lao, H.Y. Liu (NAO, CAS), L.N. Xu (USTC), X.H. Tang (THU) and C.C. Jin (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 EP261007a. The transient triggered EP-WXT (ID: 01709321003) at 2026-10-07T06:47:00 (UTC). The WXT position of the source is R.A. = 11.629 deg, DEC = -17.694 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. = 11.6137 deg, DEC = -17.6933 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic).

We note that EP261007a is spatially consistent with GRB 261007A (GCN #45824, #45825). 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).