Mysterious deep space signals indicate brutal stellar phenomena
Astronomers have figured out that some mysterious, quick X-ray flashes in space—called FXTs—are actually "failed" jets stuck inside dying massive stars.
Unlike the dramatic jets that escape and make gamma-ray bursts, these ones get trapped, leading to weaker X-ray signals instead.
EP 250108a: the closest FXT spotted yet
In January 2025, the Einstein Probe spotted the closest FXT yet, named EP 250108a.
Follow-up from telescopes like Keck and James Webb showed it came from a supernova of a star way bigger than our Sun, but its jet never broke out—so we saw X-rays but no gamma-ray burst.
More types of cosmic explosions are out there than realized
This discovery shakes up what scientists thought about exploding stars.
Turns out, trapped jets might be pretty common when huge stars die—not just rare flukes—which means there are more types of cosmic explosions out there than we realized.