Einstein Probe detects X-ray transient EP260227a with optical counterpart at z=2.714

AI Summary

The Einstein Probe WXT detected a bright X-ray transient (EP260227a) on 2026-02-27 at 20:12:29 UTC with a ~250 second duration and 0.5-4 keV flux of 4.1×10⁻¹⁰ erg/s/cm². An optical counterpart was rapidly identified and extensively followed up by multiple ground-based telescopes, with r-band magnitudes ranging from ~20.2 to ~24.8 AB mag over ~4 days, showing a slow fading trend. Spectroscopic observations with GTC/OSIRIS+ determined a redshift of z=2.714, establishing this as a high-redshift transient event with multi-wavelength coverage from X-ray to optical bands.