Webb Telescope Discovers Oldest Supernova in Cosmic History

A groundbreaking discovery has emerged from the James Webb Space Telescope, which has traced a powerful gamma-ray burst back to the earliest known supernova ever observed. This stellar explosion occurred when the universe was just 730 million years old, significantly earlier than any previously recorded supernova, which occurred 1.8 billion years after the Big Bang.

The event was initially detected on March 14, 2023, by the SVOM mission, a space-based observatory designed to monitor variable astronomical objects. Almost immediately, three other telescopes were employed to pinpoint the origin of the gamma-ray burst. The findings were confirmed by the Webb telescope on July 1, 2023, marking a significant milestone in our understanding of the early universe.

Andrew Levan, a professor of astrophysics at Radboud University in the Netherlands and the lead author of a study published in Astronomy and Astrophysics Letters, highlighted the importance of this observation. “Only Webb could directly show that this light is from a supernova,” he stated. “This observation also demonstrates that we can use Webb to find individual stars when the Universe was only 5% of its current age.”

Significance of the Discovery

Gamma-ray bursts, which typically last only a few seconds, are among the most energetic events in the universe. They may result from the collision of neutron stars or between a neutron star and a black hole. The gamma-ray burst in question lasted for an extraordinary 10 seconds, indicating it was likely caused by the explosive death of a massive star.

This particular supernova is rare, with Levan noting that there have been only a handful detected from the first billion years of the universe within the last half-century. “This particular event is very rare and very exciting,” he remarked.

Observations conducted by the Webb telescope revealed that the supernova’s brightness increased over a few weeks, making it easier to identify. The light from this ancient event, however, was affected by the expansion of the universe, causing it to stretch over time. Consequently, it took longer for the light to reach Earth.

Comparative Analysis with Modern Supernovae

Upon studying the supernova, astronomers compared it to more recent explosions closer to Earth. Surprisingly, they found that this ancient supernova bears a striking resemblance to its modern counterparts. Stars in the early universe had fewer heavy elements and were generally more massive, suggesting they should exhibit different characteristics.

“We went in with open minds,” said Nial Tanvir, a professor at the University of Leicester and co-author of the study. “And lo and behold, Webb showed that this supernova looks exactly like modern supernovae.”

The research team plans to leverage the capabilities of the Webb telescope further to observe the afterglow of distant gamma-ray bursts. This data will provide insights into the evolution of galaxies and the conditions in the early universe. “That glow will help Webb see more and give us a ‘fingerprint’ of the galaxy,” noted Levan.

The findings from this unprecedented observation not only push the boundaries of our cosmic knowledge but also illustrate the evolving capabilities of space telescopes to explore the universe’s history. As research continues, the James Webb Space Telescope promises to unlock even more mysteries of the cosmos.