Einstein Probe detects transient X-ray event EP261025a with initial high signal-to-noise ratio

AI Summary

The Einstein Probe WXT detected a short-duration (130 seconds) X-ray transient, EP261025a, which was followed up by the FXT yielding a refined position and spectral parameters indicating an absorbed power-law model with photon index 1.68. Subsequent FXT observations showed no significant X-ray emission.

Measurements

Notices (1)

Einstein Probe WXT — GRB · Sun, 25 Oct 2026 07:19:57 GMT

GCN Circulars (3)

GCN-46076 — EP261025a · Thu, 29 Oct 2026 03:14:14 GMT
The Einstein Probe (EP) detected a transient event, EP261025a, with the Follow-up X-ray Telescope (FXT) on October 25, 2026. The first observation detected an X-ray counterpart with a refined position and specific spectral parameters, while the second observation did not detect significant X-ray emission. The event is significant for further multiwavelength observations.

GCN-46028 — EP261025a · Sun, 25 Oct 2026 17:27:59 GMT
Astronomers observed the field of EP261025a in the near-infrared J band using the Palomar 1-m telescope with the WINTER camera, but did not detect any new source, establishing a 5-sigma upper limit of J = 18.9 mag (AB). This observation was conducted 5.45 hours after the WXT light curve began, and an optical upper limit was also reported by Mandarakas et al.

GCN-46025 — EP261025a · Sun, 25 Oct 2026 14:08:43 GMT
The Einstein Probe's Wide-field X-ray Telescope detected a fast X-ray transient, EP261025a, lasting approximately 130 seconds. A follow-up observation with the Follow-up X-ray Telescope identified an uncatalogued X-ray source within the error circle, prompting a call for multi-wavelength observations.