Astronomers have discovered something extraordinary in our own galaxy: the first known microblazar in the Milky Way. This unusual system contains a black hole and a massive star, and its powerful jet is aimed almost directly toward Earth.
Even more remarkably, researchers have found evidence that the jet is slamming into a dense cloud of gas and dust, creating a powerful region where particles may be accelerated to petaelectronvolt (PeV) energies—among the highest particle energies known in the Universe.
If confirmed, this makes the newly identified system a natural particle accelerator potentially around 100 times more powerful than the Large Hadron Collider (LHC).
The international research team, involving scientists from ASTRON, JIVE, the University of Amsterdam and other institutions, reported the discovery in Astronomy & Astrophysics.
What Is a Microblazar?
To understand this discovery, it helps to first understand a blazar.
Black holes can pull matter toward themselves through their enormous gravitational fields. When a black hole feeds on surrounding material, the material can form a rapidly rotating disk around it. As some of this matter falls toward the black hole, a portion can be redirected outward through powerful jets emerging from the black hole's poles.
These jets can contain extremely energetic particles and radiation traveling at speeds close to that of light.
When one of these jets happens to point toward Earth, the object can appear exceptionally bright. Such objects are called blazars.
Blazars are usually associated with supermassive black holes at the centers of distant galaxies. But a microblazar is essentially a smaller version of this phenomenon, involving a stellar-mass black hole.
Scientists had predicted that microblazars should exist for roughly three decades. Now, they have identified the first convincing example in our galaxy.
A Black Hole Feeding on a Massive Star
The newly studied system is called IRAS 18293−0941.
At its center is a black hole estimated to have a mass of about 10 times that of the Sun. It is orbiting a hot, massive companion star, with the two objects completing an orbit roughly every 11 days.
The black hole's powerful jet is created because it is pulling material from its companion star.
The process is similar to cosmic recycling. Gas from the star is captured by the black hole and begins forming a rapidly rotating accretion disk around it. Before all of this material can disappear into the black hole, some of it is expelled through powerful jets.
In this case, one of those jets is directed toward Earth, giving the system its microblazar appearance.
The Jet Travels Through Space—and Then Hits a Cloud
Radio observations provided an important clue about what is happening around the system.
The jet first travels through a huge region of interstellar space extending for roughly 100 light-years. During this journey, it appears to have cleared out much of the surrounding interstellar material.
But the jet eventually encounters something much denser: a molecular cloud.
Molecular clouds are enormous collections of cold gas and dust, containing large amounts of molecular hydrogen. They are also important because they are the places where new stars can eventually form.
When the black hole's jet crashes into this cloud, the interaction produces a bright region. The enormous energy carried by the jet heats the surrounding material and ionizes the gas.
But something even more interesting happens there.
A Natural Particle Accelerator
The collision between the jet and the molecular cloud creates an extremely energetic environment.
Researchers found that the bright region coincides with a gamma-ray signature associated with high-energy particles. Their analysis suggests that particles may be accelerated to energies reaching the petaelectronvolt range.
One petaelectronvolt is equal to one million billion electronvolts.
These are extraordinary energies.
Scientists have detected cosmic particles reaching PeV energies on Earth, but one major mystery has remained: where are these particles actually accelerated?
For more than a century, researchers have studied cosmic rays, yet the exact locations responsible for producing the most energetic particles have been difficult to identify.
The newly discovered microblazar provides a promising candidate.
Its powerful jet acts like a gigantic natural accelerator, while the collision with the molecular cloud creates conditions capable of pushing particles to extreme energies.
More Powerful Than Humanity's Biggest Accelerator
The researchers estimate that this cosmic accelerator could reach energies roughly 100 times higher than those produced by the Large Hadron Collider, the world's most powerful particle accelerator.
But there is an important difference.
The LHC is an enormous machine built by humans beneath the ground, while this microblazar is using natural astrophysical processes on a scale of light-years.
The jet carries enormous amounts of energy across interstellar space before transferring some of that energy to particles when it strikes the molecular cloud.
In other words, nature has created a particle accelerator on a scale that humans cannot reproduce.
A Mystery Hidden Since 1983
Interestingly, IRAS 18293−0941 is not a newly discovered object.
It was first catalogued in 1983 by the Dutch-American Infrared Astronomical Satellite, or IRAS.
Astronomers had already noticed something unusual about the system. Radio observations showed a bright, compact core accompanied by radio emission extending predominantly on one side.
That asymmetry hinted that a powerful jet might be present.
However, proving what was happening required observations across several parts of the electromagnetic spectrum.
The researchers therefore organized an extensive multiwavelength observing campaign.
Radio telescopes provided detailed images of the jet and its interaction with surrounding material. Optical observations helped researchers study the system's spectrum and motion. X-ray and gamma-ray observations revealed information about the extremely hot and energetic environment, while infrared observations helped reveal the warm dust surrounding the system.
No single telescope could have provided the complete picture.
Together, the observations allowed astronomers to connect the black hole, its jet, the molecular cloud and the high-energy particles.
Why This Discovery Matters
The discovery is important for more than just understanding one strange black-hole system.
Microblazars could provide astronomers with a nearby laboratory for studying the physics of blazars.
Supermassive black-hole blazars have been observed in distant galaxies, but they are so far away that astronomers often cannot resolve their individual structures in detail.
A microblazar inside the Milky Way is different.
Because it is much closer, researchers can study its jet and surroundings in far greater detail.
That makes IRAS 18293−0941 a kind of nearby laboratory for understanding much larger cosmic systems.
The discovery could also improve our understanding of cosmic rays and the processes that produce the Universe's most energetic particles.
The Jet Could Also Affect Star Formation
There is another intriguing consequence.
The jet is interacting with a molecular cloud—the same kind of environment where stars are born.
The energy deposited by the jet can heat and ionize the cloud, potentially changing its physical conditions.
Scientists therefore want to investigate whether microblazars can influence the formation of stars and the larger structure of their host galaxies.
Further observations of the jet's impact point could reveal exactly how energy from the black hole is transferred into the surrounding gas and dust.
A New Window Into Black-Hole Physics
The discovery of the Milky Way's first microblazar demonstrates how much more there is to learn about black holes.
A relatively small stellar-mass black hole, feeding from a nearby star, can launch a jet powerful enough to influence material across dozens of light-years and potentially accelerate particles to extraordinary energies.
Most importantly, the discovery shows why modern astronomy increasingly relies on multiple types of telescopes working together.
Radio, optical, infrared, X-ray and gamma-ray observations each revealed a different part of the story. When combined, they exposed a remarkable cosmic system that had remained hidden in plain sight for decades.
The researchers now plan additional observations of the region where the jet crashes into the molecular cloud.
That region could hold important clues about one of astronomy's oldest mysteries: where the most energetic particles in our galaxy are born.
And somewhere in the darkness of the Milky Way, a small black hole may be providing the answer—using a natural particle accelerator far more powerful than anything humanity has ever built.
Reference: Josep Martí et al, A Galactic microblazar as a potential accelerator of ultra-high-energy particles, Astronomy & Astrophysics (2026). DOI: 10.1051/0004-6361/202661105.
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