GCN Circular 43849

Subject

The EP-WXT trigger 01709258652 is likely a flaring star

Date

2026-02-26T16:09:54Z (6 days ago)

From

EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

Via

Web form

Guojiong Yang, Tong Zhao(Nao, CAS), Zecheng Zou(NJU) and Wenda Zhang(Nao, CAS) on behalf of the Einstein Probe (EP) team:

The EP-WXT trigger 01709258652 at the time of 2026-02-26T13:49:59(UTC), is likely a stellar flare associated with LP 435-538. The WXT position of the source is R.A. = 190.202 deg, DEC = 19.917 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). The estimated flux of the flare is around 8e-11 erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 2.071e+31 erg/s.

A follow-up observation with the Follow-up X-ray Telescope (FXT) was performed automatically. An onboard alert was generated by FXT during this observation and the FXT position is R.A. = 190.1724 deg, DEC = 19.9231 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic). The FXT position is consistent with the star LP 435-538.

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).