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A Cosmic Explosion Leaves a Magnetic Fingerprint
The VLA detected polarized radio afterglow and Faraday rotation from a gamma-ray burst for the first time.
Summary
The VLA detected polarized radio afterglow and Faraday rotation from a gamma-ray burst for the first time.
Astronomers using the NSF Very Large Array measured polarized centimeter-wave radio light from GRB 260310A and found its polarization angle changed with wavelength. That Faraday rotation encodes the magnetized material crossed by the light and had not previously been detected in a gamma-ray burst. The inferred field was too strong to be explained by the Milky Way or intergalactic space alone, pointing instead to a dense ionized region around the exploded star. One unusually bright nearby burst does not establish that every gamma-ray burst has the same environment.
Why it matters
The VLA detected polarized radio afterglow and Faraday rotation from a gamma-ray burst for the first time.
Limits and context
- That Faraday rotation encodes the magnetized material crossed by the light and had not previously been detected in a gamma-ray burst.
- One unusually bright nearby burst does not establish that every gamma-ray burst has the same environment.
Key claims
The VLA detected polarized radio afterglow and Faraday rotation from a gamma-ray burst for the first time.
Qualification: That Faraday rotation encodes the magnetized material crossed by the light and had not previously been detected in a gamma-ray burst.
Evidence: source-2026-07-15-014
Sources
- NSF NRAO via Newswise: Magnetic fingerprint of a cosmic explosionNSF NRAO via Newswise · secondary reporting
Corrections
No corrections have been recorded for this story.