A cosmic light show

Space is lowkey obsessed with secrets, and astronomers just cracked a big one. Usually, when two neutron stars—the super dense remains of dead massive stars—crash into each other, they let off a quick blast of gamma rays that vanishes in under two seconds. But this time? The plot thickens.

Astronomers identified an event, EP250704a/GRB 250704B, which had a half-second gamma-ray burst but kept glowing with bright X-rays for nearly ten minutes. This is the longest prompt X-ray flash ever seen from a neutron star merger, and it’s giving major main character energy.

Solving the mystery

Since the Einstein Probe satellite launched in 2024, it’s been catching tons of "fast X-ray transients"—essentially mysterious flashes from deep space. Figuring out what causes them is a struggle because they’re often super far away.

Graduate student Niccolò Passaleva was actually on a train when he got the alert. He had to rush to secure time on the European Southern Observatory’s Very Large Telescope (VLT) from his laptop while the event was still happening. By breaking the light down, his team confirmed the source was over six billion light-years away—meaning this light started its journey way before our solar system was even a thing.

The magnetar connection

The team didn't find the supernova explosion you'd expect if a massive star had just collapsed. Instead, they found strong evidence that the merger created a magnetar. These are neutron stars that spin fast and pack huge magnetic fields.

"When they damp their magnetic power into the surroundings, they can make any explosion brighter and longer-lasting," explained Professor Eleonora Troja.

Why it matters

This discovery is a massive W for astronomy. It proves that some of those mysterious space flashes are actually the birth cries of magnetars. If researchers can link more of these X-ray flashes to gravitational waves in the future, they’ll be able to map out exactly how often these intense collisions happen and what they leave behind. It’s early days, but the potential to unlock more secrets of the universe is highkey real.