A team led by Manisha Caleb of the University of Sydney used the James Webb Space Telescope to find the home galaxy of FRB 20240304B, a millisecond radio flash caught by South Africa’s MeerKAT array on 4 March 2024. Webb’s NIRSpec instrument measured a redshift of 2.148, so the burst set off about 3 billion years after the Big Bang — the most distant fast radio burst known. Its host is a small, young dwarf galaxy busy forming stars, roughly 1,000 times less massive than expected and too faint for Keck and other ground-based telescopes to see. Because the galaxy built most of its stars within about 30 million years, the team favours young magnetars over neutron-star mergers as the source. The results were published in Science on 8 October 2026. Our take: fast radio bursts are still a puzzle, but this one points firmly at young, super-magnetised dead stars.
z = 2.148redshift, a new record
~3 bnyears after the Big Bang