Astronomers Identify the Strongest Candidate Yet for a “Microblazar”

Researchers have identified the strongest candidate to date for a microblazar—a dazzling cosmic object long predicted to exist but never definitively observed.

Studying microblazars could give astronomers a closer look at black holes that produce powerful jets of energy, helping scientists understand how these extreme objects behave.

What is a microblazar?

Blazars are among the most energetic objects in the universe. They are a type of quasar powered by a supermassive black hole that draws in matter from its host galaxy.

As matter falls toward the black hole, some of it can be expelled in two powerful, opposing jets of particles and radiation. A blazar is formed when one of those jets points directly toward Earth.

Quasars are energized by supermassive black holes, while microquasars are smaller systems with stellar-mass black holes. Astronomers have long theorized that a smaller counterpart to a blazar—a microblazar—should also exist.

A black hole 12,000 light-years away

An international team led by astronomers from Spain, the Netherlands and Argentina has described a promising microblazar candidate in a study accepted for publication in Astronomy & Astrophysics.

“This is the first time we have a serious candidate,” Josep Martí, an astronomer at the University of Jaén in Spain and the study’s lead author, told Live Science.

The object, known as IRAS 18293−0941, is located in the Milky Way about 12,000 light-years from Earth. It is hidden behind a veil of dust and consists of a binary star system: a black hole orbiting a hot, massive star once every 11 days.

Material from the companion star falls toward the black hole. Some of that material is then ejected into space in two opposing jets, one of which is directed toward Earth.

Why microblazars are difficult to find

Microblazars, like microquasars in general, are difficult to observe because the relevant stage in a star system’s evolution is brief.

“We need to capture the system at the right time for the evolution of the star,” Martí said. “The evolutionary stage of a microquasar is very short, so it’s difficult to find a microquasar at that stage.”

Theorists have predicted that microblazars should display several distinctive characteristics, including strong radiation across the electromagnetic spectrum, rapid changes in brightness and hotspots located behind the system.

These hotspots could form when the opposing jets heat the interstellar medium in the direction away from Earth.

Observations reveal most expected features

To investigate IRAS 18293−0941, the researchers used observations from the Calar Alto Observatory in Spain, the European VLBI Network, the MeerKAT radio telescope array in South Africa and archival data from the Very Large Array in New Mexico.

The object displayed all of the expected characteristics of a microblazar except one: rapid variability.

In a microblazar, a jet pointed toward Earth should make small changes in brightness appear much larger over short periods. This effect, known as Doppler boosting, occurs because the jet’s near-light-speed motion amplifies the radiation directed toward Earth.

IRAS 18293−0941 does not show those rapid fluctuations. Martí said the system’s dense surrounding gas cloud could be smoothing out short-term changes in brightness.

Researchers are also investigating whether the regions observed behind the object are actually hotspots, according to study co-author Pedro Luque Escamilla and his colleagues at the University of Jaén.

Is this the first confirmed microblazar?

Although IRAS 18293−0941 lacks one expected feature, it remains a promising candidate for the first known microblazar.

“The paper’s claims and results are reasonable and there are no questionable hidden assumptions,” Kinwah Wu, a theoretical astrophysicist at University College London who was not involved in the study, told Live Science by email. He said the observations show signs of interaction between the jet and the surrounding material.

Svetlana Jorstad, a senior researcher at Boston University’s Institute of Astrophysics who was also not involved in the study, described the research as “very interesting, important, and comprehensive.”

Astronomers at the University of Cape Town added that the observations point to a previously overlooked mechanism capable of producing some of the highest-energy emissions observed.

Microblazars “have the potential to power some of the most energetic processes in the universe,” astronomer Itumeleng Monageng told Live Science in an email.

Further observations will be needed to determine whether IRAS 18293−0941 truly is a microblazar and whether the structures behind it are genuine jet-powered hotspots.

Study reference

Martí, J., Luque-Escamilla, P. L., Marcote, B., Abaroa, L., Aguasca-Cabot, A., Combi, J. A., Romero, G. E., Paredes, J. M., García, F., Fogantini, F., Saavedra, E. A., Del Ser, D., and Van Den Aijnden, J. (2026). Galactic microblazers as potential accelerators of ultrahigh-energy particles. Astronomy & Astrophysics.

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