An October 2026 study links distant radio flares with high-energy neutrinos detected in Antarctica, offering a promising new way to investigate some of the universe’s most powerful objects.
Scientists have found new evidence that radio telescopes could help identify the distant cosmic objects producing some of the universe’s most energetic neutrinos. A study published October 9, 2026, found a possible connection between radio signals from active galaxies and high-energy particles detected by the IceCube Neutrino Observatory in Antarctica.
The research suggests that radio flares, which are temporary increases in radio brightness, may be associated with approximately 13% of the astrophysical neutrinos observed by IceCube. The finding offers a promising way to search for the origins of particles that can travel across enormous distances without interacting with matter.
The results appeared in The Open Journal of Astrophysics, in a study led by physicist Yjan Gordon of the University of Wisconsin–Whitewater. Researchers Peter Ferguson, Eric Hooper and Michael Martinez also contributed to the investigation.
Although the findings are encouraging, the researchers cautioned that the connection has not yet reached the level of statistical certainty normally required to establish a discovery.
What Are Neutrinos and Why Are They Difficult to Detect?
Neutrinos are extremely small subatomic particles with tiny masses and no electrical charge. They are produced by nuclear reactions in stars, radioactive decay and some of the most energetic events in the universe.
Even ordinary objects can emit neutrinos. Bananas, for example, contain small amounts of radioactive potassium-40, which can decay through a process that produces neutrinos.
The Sun also produces enormous numbers of neutrinos through the nuclear reactions that generate its energy.
What makes neutrinos particularly difficult to study is their tendency to pass through matter almost without leaving a trace. Most travel through Earth, buildings and human bodies without interacting with anything.
Unlike electrically charged particles, neutrinos do not experience electromagnetic forces. Their interactions with ordinary matter primarily involve the weak nuclear force and gravity.
The weak force operates over extremely short distances, making interactions between neutrinos and other particles exceedingly rare.
Scientists have nevertheless developed instruments capable of detecting the occasional interaction. These detectors use enormous volumes of material to increase the chances of capturing evidence that a neutrino has passed through.
IceCube Uses Antarctic Ice to Detect Cosmic Particles
One of the most important neutrino observatories is IceCube, located at the geographic South Pole.
The facility uses approximately one cubic kilometer of Antarctic ice as a giant particle detector. Thousands of light-sensitive instruments are installed deep beneath the surface.
When a neutrino occasionally interacts with an atomic nucleus in the ice, it can produce electrically charged particles. These particles may travel through the ice fast enough to generate a faint blue glow called Cherenkov radiation.
IceCube’s sensors detect that light, allowing scientists to estimate the energy and incoming direction of the neutrino.
The observatory has helped establish that extremely energetic neutrinos reach Earth from beyond the solar system. Some carry far more energy than neutrinos produced by ordinary nuclear reactions.
These particles offer astronomers a different way to investigate distant environments. Unlike light, which may be absorbed or scattered by surrounding material, neutrinos can escape from dense regions of space and travel toward Earth.
IceCube’s importance received international recognition on October 6, 2026, when physicist Francis Halzen was awarded the Nobel Prize in Physics for his contributions to the observatory and the discovery of high-energy astrophysical neutrinos.
Halzen, a professor at the University of Wisconsin–Madison, played a major role in developing IceCube and establishing its scientific program.
Scientists Search for the Sources of High-Energy Neutrinos
One of the biggest remaining questions in neutrino astronomy concerns where these powerful particles originate.
Astronomers suspect that some are produced near supermassive black holes, which can contain millions or billions of times the Sun’s mass.
Many of these black holes occupy the centers of active galaxies. As surrounding material falls toward them, it heats up and releases enormous amounts of energy.
Some active galaxies also produce powerful jets of particles that travel outward at speeds approaching the speed of light.
When one of these jets points roughly toward Earth, astronomers classify the source as a blazar, a type of active galactic nucleus. Blazars can produce intense radiation across several wavelengths, including radio waves and gamma rays.
Scientists believe that interactions involving energetic particles inside or near these jets may produce neutrinos.
In September 2017, IceCube detected a high-energy neutrino arriving from the direction of a blazar called TXS 0506+056.
Around the same time, astronomers observed an increase in gamma-ray emissions from the object. The combination provided important evidence that active galaxies could produce high-energy neutrinos.
However, scientists have not identified the sources of most neutrinos detected by IceCube. The relationship between neutrino production and the radiation emitted by distant galaxies remains an active area of research.
Radio Telescope Survey Reveals Possible Connection
The latest investigation used observations from the Karl G. Jansky Very Large Array, a powerful radio telescope system in New Mexico.
The facility consists of 27 radio antennas working together to observe astronomical objects.
Beginning in 2017, astronomers used the telescope system to conduct the Very Large Array Sky Survey, known as VLASS.
The survey repeatedly observes large portions of the sky, allowing researchers to detect objects whose radio brightness changes over time.
Gordon’s team compared the first two rounds of VLASS observations with records of high-energy neutrinos detected by IceCube.
The researchers wanted to determine whether radio sources that became brighter were more likely to appear near the estimated arrival directions of neutrinos.
They found more associations between radio flares and neutrino detections than would generally be expected from random alignments.
The pattern was strongest when the neutrinos arrived during the period between the two radio observations.
According to the published study, the excess associations were consistent with radio flares contributing approximately 13% of the astrophysical neutrinos in the IceCube sample.
The findings suggest that at least some of the particles may originate in objects undergoing periods of increased radio activity.
However, the researchers did not establish that individual radio flares caused specific neutrino detections.
Most Associated Radio Flares Were Invisible to Higher-Energy Telescopes
One particularly interesting finding involved the absence of signals at other wavelengths.
The researchers reported that approximately 90% of the radio flares associated with neutrinos were not detected by gamma-ray or X-ray telescopes.
This raises the possibility that some neutrino-producing objects are difficult to identify through conventional high-energy astronomical observations.
Radio waves can sometimes escape from regions where higher-energy radiation is absorbed or difficult to observe.
Consequently, radio telescopes may help astronomers identify candidate neutrino sources that other instruments miss.
The study also found that many radio-variable objects were quasars or related active galaxies, supporting the possibility that supermassive black holes play a significant role in producing energetic neutrinos.
The authors emphasized that these are statistical associations rather than confirmed identifications of individual particle sources.
More Observations Are Needed to Confirm the Findings
The current evidence is promising but not yet strong enough to establish a definite connection.
The researchers reported a statistical significance slightly above two sigma. In an October 30 article for The Conversation, Gordon explained that the observed pattern had approximately a one-in-30 chance of appearing even if no real association existed.
Scientific discoveries in particle physics generally require much stronger evidence, often approaching five sigma.
Future observations from VLASS could provide the additional information needed to test the proposed relationship.
The survey’s repeated measurements will allow astronomers to examine more radio flares and compare them with additional neutrino detections.
Better estimates of neutrinos’ incoming directions could also improve the reliability of potential matches.
If the statistical relationship becomes stronger, scientists may be able to identify more of the active galaxies responsible for producing high-energy neutrinos.
The October study therefore represents a possible advance rather than a final answer. Further observations will determine whether radio flares provide a dependable way to trace the origins of these elusive cosmic particles.
IMAGE: Source Own work Author Christopher Michel (1967–) CC4