A record-breaking X-ray flash may reveal the birth of a magnetar

Astronomers have long relied on brief bursts of gamma rays to identify collisions between neutron stars. These flashes can vanish in less than two seconds. Now, new research suggests that some neutron star mergers may also produce X-ray flashes that remain visible for several minutes.

A study published in Science Bulletin presents strong evidence for that connection. The findings raise the possibility that some mysterious cosmic flashes, whose sources have been difficult to explain, may actually come from merging neutron stars.

Since the Einstein Probe satellite launched in January 2024, astronomers have detected hundreds of bright X-ray flashes from distant galaxies. These events, called fast X-ray transients, have several possible origins. Some have been connected to the deaths of massive stars, while others remain unexplained.

Determining what causes them can be difficult because astronomers often do not know how far away the events are or how much energy they release.