The observed light curve evolved over months, characteristic of cosmological time dilation rather than a brief gamma-ray burst.

Led by Andrew Levan, researchers confirmed the light originated from a collapsing massive star and highlighted JWST’s capability to directly observe such events in the early universe.

The team aims to study early galaxies further by capturing afterglows of gamma-ray bursts and plans rapid-turnaround observations for future events.

A gamma-ray burst from GRB 250314A, linked to the death of a massive star, signals a supernova that exploded about 13 billion years ago, placing the event when the Universe was roughly 730 million years old.

Initial detection came from the mid-March SVOM mission, with rapid follow-up from NASA’s Swift Observatory and ground-based facilities, including the Nordic Optical Telescope and the European Southern Observatory’s Very Large Telescope.

This event marks the oldest recorded supernova to date, surpassing previous records by more than a billion years and demonstrating JWST’s ability to study individual stars from the early Universe.

The findings are published in Astronomy & Astrophysics, December issue, with attribution to the research team led by Emeric Le Floc’h and journalist Keith Cooper.

Key researchers, including Andrew Levan as lead author and Nial Tanvir, coordinated observations across SVOM, Swift, and ESO facilities to enable rapid, multi-instrument study.

Researchers note surprising similarities between this ancient supernova and modern ones, informing understanding of early star formation and galactic environments during the Era of Reionization.

The release highlights collaboration among NASA, ESA, and CSA, and points readers to related science papers and official release links for more details.

JWST detected the supernova’s host galaxy, which appears as a smeared, faint image, suggesting a galactic environment similar to other early-universe galaxies.

In July, JWST confirmed the flash was a supernova and identified the host galaxy as a small red smudge.

Compared with modern stars, the earliest supernovae are expected to be more massive and formed from lighter elements in a denser, smaller early universe.

The explosion is tied to GRB 250314A, indicating the death of a massive star and the possible birth of a stellar-mass black hole.

The same GRB designation reinforces the link between the gamma-ray burst and the associated supernova.

The study is published across two papers in Astronomy & Astrophysics Letters and utilized a Director’s Discretionary Time program for rapid observations.

The event was first detected in mid-March 2025, with swift, multi-facility follow-up leading to the supernova identification.

Over months, the supernova brightened and its light curve stretched due to cosmic expansion, allowing comparison with modern nearby supernovae.

Cosmic time dilation caused the peak brightness to occur months after the initial burst, consistent with expectations for such an ancient event.

JWST followed up mid-year to capture high-resolution near-infrared images and locate the faint host galaxy associated with the GRB.

JWST provided the first direct view of the supernova’s host galaxy, a breakthrough despite the galaxy appearing as a reddened smudge.

The host galaxy’s faint, reddened appearance limits detailed measurements, but its detection marks a significant step in studying reionization-era galaxies.

Spectral analysis shows the supernova shares traits with modern Type-like core-collapse supernovae, implying a massive-star progenitor in an environment with low heavy-element abundance.

JWST’s NIRCam captured the supernova light on July 1, enabling direct observation of a supernova from such an early epoch.