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Selections from 2025: Pinpointing a Bright Fast Radio Burst with CHIME

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JWST image of the galaxy NGC 4141
JWST image of the galaxy NGC 4141, site of the fast radio burst FRB 20250316A. [NASA/ESA/CSA/CfA/P. Blanchard et al.; Image processing: CfA/P. Edmonds]

Editor’s Note: For the remainder of 2025, we’ll be looking at a few selections that we haven’t yet discussed on AAS Nova from among the most-downloaded articles published in AAS journals this year. The usual posting schedule will resume January 2nd.

FRB 20250316A: A Brilliant and Nearby One-Off Fast Radio Burst Localized to 13 pc Precision

Published August 2025

Main takeaway:

NGC 4141

MMT observation of NGC 4141 (left) and zoomed-in on FRB 20250316A’s location. The red lines show the 1-, 2-, and 3-sigma localization ellipses of the burst. Click to enlarge. [CHIME Collaboration 2025]

Discovered in March 2025 by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) Outrigger array, FRB 20250316A is one of the brightest fast radio bursts ever observed. The CHIME collaboration traced the burst to the galaxy NGC 4141, 130 million light-years from Earth, and locked in on the source’s position with a precision of just 42 light-years.

Why it’s interesting:

The origins of fast radio bursts — bright flashes of radio waves lasting on the order of milliseconds — are mysterious, despite several thousand bursts having been cataloged. Among the many questions that remain is whether one-off bursts and repeating bursts arise from the same population of objects, or if they have entirely different origins. So far, FRB 20250316A appears to be a one-off burst; while it’s still possible that the source could emit another burst, the team noted that the burst’s properties don’t mesh with those of known repeating bursts. This makes the discovery and localization of FRB 20250316A an excellent opportunity to investigate the sources of one-off fast radio bursts.

More about the potential source of this burst, and prospects for pinpointing future sources:

After homing in on FRB 20250316A’s location, the CHIME collaboration embarked on a multi-wavelength follow-up campaign to learn more about where the burst came from. This campaign placed constraints on the metallicity and gas density near the source, which lies about 600 light-years from the center of the nearest star-forming region. A separate research article, published the same day as this work from the CHIME collaboration, described the discovery of a red giant star in the FRB 20250316A source region. This star may be located near FRB 20250316A’s source by chance, or it could be in a binary system with the source. With the main CHIME array in British Columbia continuing to scan for new bursts and three newly built outrigger telescopes in British Columbia, West Virginia, and California now online, we can expect many more precise localizations in the future!

Citation

The CHIME/FRB Collaboration: et al 2025 ApJL 989 L48. doi:10.3847/2041-8213/adf62f