China’s Einstein Probe (EP) satellite has detected a previously unknown type of cosmic explosion involving weak and fast X-ray transients that occur during the death of massive stars.
The discovery, published in the latest issue of the journal Nature Astronomy, challenges existing theories of star collapse and reveals a hidden class of stellar explosions.
The satellite captured a mysterious 150-second X-ray burst, named EP240414a, from a dying star 4 billion light-years away. Subsequent observations confirmed its connection to the rare supernova SN 2024gsa and revealed a faint relativistic jet similar to gamma-ray bursts, but slower and less energetic.
EP’s advanced wide-angle X-ray telescope allowed scientists to track the evolution of the jet, providing important evidence for understanding both the mechanisms of jet formation and the basic physics of supernova explosions.
“These fast X-ray transients are like cosmic fireworks, bright and fleeting, making them extremely difficult to detect,” said lead author Gao He of Beijing Normal University. “Past missions have missed them due to limited detection capabilities.”
“This is the first discovery of an X-ray transient associated with a supernova, marking a new era in high-energy astrophysics,” added study co-author Wang Xiaofeng of Tsinghua University.
Launched in January 2024, the EP uses advanced lobster-eye optics to monitor the X-ray sky with unparalleled sensitivity.
“EP240414a demonstrates EP’s ability to discover new cosmic phenomena,” said EP principal investigator Yuan Weimin of the National Astronomical Observatory of the Chinese Academy of Sciences.
Scientists expect new discoveries as the mission continues to explore the dynamic Universe.
