Einstein Probe Detects Record-Breaking X-ray Flash Linked to Neutron-Star Collision

The Einstein Probe space telescope, operational since January 2024, has been monitoring rapid X-ray bursts whose origins remain largely unknown. A new detection, labeled EP250704a/GRB 250704B, was captured by three satellites, beginning with a brief half-second gamma-ray burst. This was succeeded by an X-ray flash lasting close to ten minutes from the same sky region, the longest such signal linked to a neutron-star collision so far.

Researchers ruled out a supernova as the cause and concluded that two neutron stars likely merged, possibly forming a magnetar whose intense magnetic field prolonged the emission. While this finding does not prove that all fast X-ray transients arise from such mergers, it provides a compelling case and motivates further observations to assess how often magnetars result from these events.