General information
EP260903a is a fast X-ray transient detected by the Einstein Probe Wide-field X-ray Telescope, starting around 2026-09-03T11:17:59 UTC. The reported position is RA = 292.004 deg, Dec = -21.494 deg with a 2.6 arcmin 90% uncertainty radius.
Wavelength coverage
- X-ray: EP-WXT detected the transient in the 0.5-4 keV band; EP-FXT follow-up was scheduled.
- Optical: MASTER-Net follow-up is mentioned, but no observational result is included in the provided circular.
No radio, gamma-ray, infrared, ultraviolet, neutrino, or gravitational-wave observations are mentioned.
Lightcurve and spectrum
- The WXT light curve lasted approximately 200 s.
- The light curve showed a double-peaked structure.
- The average WXT 0.5-4 keV spectrum is fit by an absorbed power-law model with fixed Galactic hydrogen column density of 8.0×10^20 cm^-2.
- The photon index is 1.67 (-0.54/+0.60).
- The average unabsorbed 0.5-4 keV flux is quoted as 7.41 (-2.21/+2.90) erg cm^-2 s^-1 in the circular text.
Redshift
What’s special vs typical
- The event is notable for being a very short, fast X-ray transient with a reported double-peaked structure.