A stunning flash of light, termed a **gamma-ray burst**, traveled over 13 billion years to reach Earth. This brief yet powerful event unfolded in a universe that was just beginning, predating the formation of galaxies like ours. The burst lasted only **ten seconds**.
Initially, its origin was a mystery. As scientists gathered data from various telescopes, they realized they were witnessing something unprecedented. It was either a collapsing star or a mysterious type of stellar explosion yet to be classified.
While gamma-ray bursts are regularly detected and studied, this one was unique. Its long journey and the way it unfolded set it apart from any other burst observed to date.
Ultimately, this event made history. The light source originated from a supernova that erupted when the universe was merely 730 million years old. It isn’t just the most distant supernova recorded, but it could also change how researchers understand star formation in the early universe.
On **March 14, 2025**, the **SVOM** (Space-based multi-band astronomical Variable Objects Monitor) satellite, a joint French-Chinese mission, flagged a gamma-ray burst lasting ten seconds. Long gamma-ray bursts are often linked to the death of massive stars and the birth of black holes, sending forth intense beams of energy visible across vast distances.
SVOM’s success in detecting what was later named **GRB 250314A** was remarkable, especially as the mission had just started full operations. Researchers from institutions like the **Observatoire de Paris – PSL** confirmed that the burst occurred during the **Epoch of Reionisation**, when the first stars and galaxies began to ionize the intergalactic medium.
Just hours after its detection, NASA’s **Neil Gehrels Swift Observatory** pinpointed the gamma-ray source. Follow-up observations from the **Nordic Optical Telescope** and **Very Large Telescope** revealed an infrared afterglow, allowing scientists to measure a **redshift of 7.3**. This indicated the light traveled more than 13 billion years to reach us.
Only a few gamma-ray bursts have ever been detected from such an early point in cosmic history. According to an update from the **European Space Agency (ESA)**, this burst now owns the record as the most distant supernova confirmed.
Three months later, the **James Webb Space Telescope (JWST)** examined the fading afterglow. This timing was crucial, as light from distant events stretches over time, appearing to linger longer than it actually did. JWST’s instruments confirmed that the burst originated from a collapsing massive star, marking the first detection of a host galaxy for such an ancient supernova.
Researchers published their findings in **Astronomy & Astrophysics Letters**, noting how GRB 250314A shattered the previous distance record of a supernova detected at a redshift of 4.3. Andrew Levan, a professor at Radboud University, stated, “Only Webb could directly show that this light is from a supernova.”
The team meticulously planned their observations to capture the burst at peak brightness, understanding that light from such events stretches dramatically over large distances.
Surprisingly, the analysis revealed characteristics that challenged previous assumptions about early supernovae. Rather than showing the unique traits associated with **Population III stars**—which were thought to die in energetic explosions—data indicated a standard **Type II supernova**. This suggests that processes shaping star death were occurring much earlier, just 730 million years after the Big Bang.
Nial Tanvir, a professor at the University of Leicester, highlighted the significance of these findings: “Webb showed that this supernova looks exactly like modern supernovae.” If more events validate this pattern, it could imply galaxies evolved more rapidly than scientists believed, producing multiple star generations in a relatively short time.
The discovery of GRB 250314A offers fresh insights into the early universe’s complexity. The collaboration between **SVOM**, **JWST**, and several ground-based telescopes confirmed the event’s nature and its environment. Gamma-ray bursts, known for their brightness, provide a powerful tool for studying cosmic history, complementing traditional deep-field imaging. Researchers plan to utilize JWST for future observations focused on similar high-redshift events, aiming to uncover more about early stellar evolution. This ongoing exploration promises to deepen our understanding of how the universe developed in its infancy.
