Einstein Probe reveals hidden phase of neutron star collisions

The Einstein Probe observatory captured event EP250704a/GRB 250704B: after a short gamma-ray flash lasting under half a second, the source emitted soft X-rays for nearly ten minutes. Observations link the emission to a compact object merger and a possible magnetar remnant.

• The gamma-ray flash lasted under 0.5 seconds, soft X-rays about 10 minutes
• Event EP250704a/GRB 250704B was detected on July 4, 2025
• Emission came from the merger remnant, not the blast wave
• A rapidly rotating magnetized neutron star (magnetar) is a plausible source