GCN Circular 41219
Subject
The EP-WXT trigger 01709198251 is likely a flaring star
Date
2025-08-02T22:16:55Z (a month ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
X. Mao (NAO, CAS), Y.-H. I. Yin (NJU), T. Zhao, C. C. Jin (NAO, CAS) on behalf of the Einstein Probe (EP) team:
The EP-WXT trigger 01709198251 at the time of 2025-08-02T20:32:45, is likely a stellar flare associated with V5663 Sgr. The estimated flux of the flare is around 1.8 x 10^-10 erg/s/cm^2 in 0.5-4.0 keV. The autonomous follow-up observation with the Follow-up X-ray Telescope (FXT) detected a source at R.A. = 301.4836, DEC = -32.2848 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic) within the WXT error circle, whose position is around 7.5 arcsec away from the high proper motion star V5663 Sgr.
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).