← stargazer

Webb Measures Distance to Farthest Fast Radio Burst, Suggesting Origin

October 8, 2026 · NASA

5 Min Read

Webb Measures Distance to Farthest Fast Radio Burst, Suggesting Origin

A field full of small galaxies of all shapes against the blackness of space. A few bright white stars show 8 prominent diffraction spikes. A small galaxy at lower right is highlighted with a white box. A shaded triangle extends upward to the corners of a larger box showing a zoom in of the region. Two fuzzy, light blue blobs are at center, with a larger and brighter one at top. Just above the top blob is a white crosshair showing the location where a fast radio burst was detected.

NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) was able to detect the host galaxy of the fast radio burst called FRB 20240304B, whose location is shown by the white cross. They found it is a small dwarf galaxy actively forming stars.

Credits:
Image: NASA, ESA, CSA, STScI, Themiya Nanayakkara (USYD); Image Processing: Joseph DePasquale (STScI)

First discovered in 2007, fast radio bursts are enigmatic, millisecond-long flashes of radio emission from the distant universe. Their origin remains uncertain, particularly since most are seen once and never again. Astronomers using NASA’s James Webb Space Telescope have pinpointed the host galaxy of the most distant fast radio burst (FRB) seen to date. Their finding has implications for what kind of energetic event creates these bursts.

“What makes fast radio bursts interesting is that we don’t know what generates them. We have theories for what objects produce them, but we don’t have conclusive proof,” said Manisha Caleb of the University of Sydney, lead author on the study published Thursday in the journal Science.

The MeerTRAP team used the MeerKAT telescope to detect the burst on March 4, 2024, leading to its designation as FRB 20240304B. The radio data from this burst suggested that it was extremely distant, possibly the most distant one seen to date. To confirm that distance, though, astronomers would need to study its host galaxy. Although they knew the location of the FRB very precisely, the world’s largest ground-based telescopes could not see any galaxy at that spot in the sky. As a result, the team turned to the Webb telescope.

Image: FRB 20240304B (NIRCam Image)

<
Read the original →