GCN Circular 37715

H.Zhou (PMO, CAS), W. Chen, H. Sun, Y. Liu (NAOC, CAS) on behalf of the Eintein Probe team

The Follow-up X-ray Telescope (FXT) on board the Einstein Probe (EP) mission performed an autonomous observation on the X-ray transient detected by EP-WXT (trigger ID 01709065118). The observation started at 2024-10-05T05:47:48 (UTC), about 4 minutes after the EP-WXT trigger time. The FXT onboard data processing system detected a source at R.A. = 344.5674 deg, DEC = -11.0724 deg (J2000) with an uncertainty of about 20 arcsec (radius, 90% C.L. statistical and systematic), consistent with the position of the WXT transient within the uncertainties. The FXT source is associated with a M-type star, 1RXS J225817.2-110434, at a distance of about 32 pc and located about 5 arcsec away from the FXT position. We suggest that this X-ray transient is likely a stellar flare event. 

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).