Karmactive Team
Astronomers have measured the host galaxy of the most distant known fast radio burst, FRB 20240304B. NASA says the burst came from an era when the universe was about three billion years old.
What was found
The burst was detected by South Africa’s MeerKAT radio telescope array. NASA’s James Webb Space Telescope then identified and measured its host galaxy using NIRCam imaging and NIRSpec spectroscopy.
Webb measured the host galaxy’s redshift at 2.148. NASA says this corresponds to a distance of 10.63 billion light-years.
Redshift measures how much light from a distant object has been stretched by the expansion of the universe. A higher redshift means astronomers are seeing the object as it was earlier in cosmic history.
The burst occurred about three billion years after the Big Bang, during a period of intense star formation often called Cosmic Noon.
What caused it?
Fast radio bursts are millisecond-long bursts of radio waves from beyond the Milky Way. Their exact causes are still being studied.
Webb’s observations show that FRB 20240304B came from a small dwarf galaxy that was actively forming stars. Magnetars—young, highly magnetic neutron stars—are a leading explanation for some fast radio bursts, but this observation does not establish the cause of this particular burst.
Why it matters
Astrophysics researchers, science communicators and observational astronomers now have a measured high-redshift host for FRB 20240304B. The result gives researchers a more precise reference point for studying fast radio bursts and the matter lying between galaxies in the distant universe. It does not confirm a magnetar origin or establish that the discovery reshapes models of early stellar evolution.
Claims that the host was a merging group of dwarf galaxies, that the finding confirms magnetar activity, or that the Square Kilometre Array will target similar bursts were not supported by the available NASA material and have been removed.
