The Sun Blasted a Mysterious Radio Signal for 19 Straight Days. Here's What We Know (Gizmodo, 5/19/26 + study)

[highplainsdem]

https://gizmodo.com/nasa-tracked-the-suns-record-breaking-radio-burst-which-lasted-for-19-days-2000760013

On August 21, 2025, the Sun emitted what appeared to be a routine burst of radio-wave energy—the kind astronomers observe regularly and expect to fade within hours or days. But this signal refused to disappear. As scientists continued to track it, the burst stretched on far beyond anything previously recorded, ultimately becoming the longest-lasting solar radio burst ever observed.

A team of researchers analyzed the event using data from four different NASA missions, which all happened to observe the radio burst for a few days over three successive windows. The record-breaking radio burst lasted for a total of 19 days, beating the previous record of just five days.

The team’s findings, published in The Astrophysical Journal Letters, helped pinpoint the exact source of the radio burst and could aid scientists in better forecasting space weather.

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The scientists have a theory as to why this particular radio burst lasted for so long. They believe that a trio of explosive outbursts, called coronal mass ejections, within the same region may have fueled the record-breaking event.

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The study is at

https://iopscience.iop.org/article/10.3847/2041-8213/ae5537

and has been published with a Creative Commons license:

Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

From the study:

The Astrophysical Journal Letters
Open access

Unprecedented 19 Day Type IV Radio Burst as a Corotating Electron Reservoir
Vratislav Krupar, Oksana Kruparova, Adam Szabo, Lynn B. Wilson III, Lan K. Jian, David Lario, Teresa Nieves-Chinchilla, Andreas J. Weiss, Anthony Iampietro, Hamish A. S. Reid, Lucie M. Green, Eduard P. Kontar, Rui F. Pinto, and Keith Goetz

Published 2026 May 14 • © 2026. The Author(s). Published by the American Astronomical Society.
The Astrophysical Journal Letters, Volume 1003, Number 1
Citation Vratislav Krupar et al 2026 ApJL 1003 L5
DOI 10.3847/2041-8213/ae5537


Abstract
We report a hectometric (0.5–3 MHz) type IV continuum observed over nearly 19 days (2025 August 21–September 9) in three successive visibility windows as the source corotates with the Sun—first at Solar Orbiter, then 12 days later in the near-Earth sector where Wind and Parker Solar Probe observed overlapping intervals, and finally 1 day later at STEREO-A—indicating a long-lived source that rotates through favorable viewing geometries. During the STEREO-A interval, the continuum is strongly left-hand circularly polarized (∣V/I∣ ≳ 0.9) and quasiperiodic pulsations (45–60 minutes). We interpret these quasiperiodic pulsations as consistent with standing fast-mode MHD oscillations of a large coronal trap. We introduce a single-spacecraft localization technique, the wavevector-corrected ray sphere (WCRS), which applies a correction to direction-finding angles combined with a coronal density model. WCRS places the source near a helmet streamer. ...

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DU's software won't allow me to copy even the full abstract. The second sentence following the excerpt above won't copy in its entirety.

The goniopolarimetric apparent half-width at the spacecraft (γ ≈ 20°) exceeds the geometric width by a factor of
, highlighting strong interplanetary scattering.

But you can read both the Gizmodo article and the study in their entirety, at the links above.

[erronis]

1. One reason the text won't copy is that the Abstract contains javascript rendering (MathJax)

the symbols following "exceeds the geometric width by a factor of" is rendered dynamically. I don't know of any good way to get around this other than substituting the graphics with typed text - probably not worth it.

[Wounded Bear]

2. That's the thing with science. The more we learn, the more we realize how little we actually know. nt

[erronis]

3. Ain't it wonderful? We can keep on learning forever!