The Einstein Probe spacecraft, which was launched on January 9, 2024, has made a groundbreaking discovery of a puzzling blast of X-rays, paving the way for new insights into gamma-ray bursts (GRBs).

On March 15, 2024, the Wide-field X-ray Telescope (WXT) aboard the Einstein Probe detected a low-energy X-ray burst, designated as EP240315a, which lasted over 17 minutes.

This event is particularly significant as it marks the first detection of soft X-rays for an extended period from an ancient explosion that occurred when the Universe was only 10% of its current age.

Interestingly, EP240315a exhibited a longer delay of over six minutes before gamma rays were detected, which challenges existing models of GRB explosions.

Researcher Xuefeng Wu noted that the Einstein Probe has shown great potential for discovering transients from the early Universe.

The unexpected characteristics of EP240315a suggest that our current understanding of GRBs may need to be reevaluated, according to Weimin Yuan, the principal investigator of the Einstein Probe.

The rapid detection of this transient event facilitated collaboration with astronomers in Italy, leading to three months of radio wavelength monitoring that confirmed the energy output was consistent with typical GRBs.

Approximately one hour after the X-ray detection, visible light from the same location was observed by a telescope in South Africa, confirming that the burst originated 12.5 billion light-years away.

The X-ray emissions detected were correlated with a GRB known as GRB 240315C, which had previously been observed by NASA's Swift Observatory and the Russian Konus instrument.

Yuan Liu from the National Astronomical Observatories, CAS, expressed satisfaction with the successful detection of this transient event, highlighting the effectiveness of the onboard software he designed for the WXT.

The mission is a collaborative effort involving the National Astronomical Observatories, the European Space Agency (ESA), the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany, and the French National Centre for Space Studies (CNES).

With its advanced sensitivity and wide field of view, the Einstein Probe is expected to lead to more discoveries regarding cosmic explosions from the early Universe.