Astronomers have identified the first microblazar within the Milky Way galaxy, a discovery that confirms a 30-year-old theoretical prediction. The system, cataloged as IRAS 18293–0941, is located approximately 12,000 light-years from Earth and features a stellar-mass black hole emitting high-speed plasma jets directly toward our planet.
Discovery of the Milky Way’s First Microblazar
An international team led by the University of Jaén identified IRAS 18293–0941 by synthesizing data from multiple wavelengths, including visible light, X-rays, gamma rays, and radio waves. While the object was initially cataloged by the IRAS satellite in 1983, its true nature remained hidden for decades behind dense interstellar dust.
According to the study, published in Astronomy & Astrophysics, the system consists of a massive, hot star and a black hole with a mass roughly ten times that of the Sun. The two objects form a binary system with an orbital period of 11.38 days. As the black hole strips material from its companion star, it creates an accretion disk. While some of this matter is consumed, the rest is ejected as bipolar jets moving at approximately 75% of the speed of light.
Confirmation via European Radio Networks
The definitive classification of the system as a microblazar—a galactic analog to the supermassive blazars found in distant galaxies—relied on high-resolution radio observations. Researchers utilized the European VLBI Network (EVN), which includes the Yebes telescope in Guadalajara, Spain.
This asymmetry occurs because one of the plasma jets is oriented almost directly toward Earth. The opposing jet, which points away, remains invisible due to relativistic effects. By cross-referencing this data with positions from the Gaia satellite, the team confirmed the system is a local stellar inhabitant rather than a distant extragalactic object.
Impact of the Microblazar on the Galactic Environment
The interaction between the system’s jets and the surrounding medium has left a significant footprint in the interstellar space of the Milky Way. Observations from the MeerKAT radio telescope in South Africa revealed a giant bubble, spanning roughly 100 light-years in diameter, carved out by the kinetic energy of the jets.
At the edge of this bubble, researchers identified a "hot spot" where the jet impacts molecular clouds. This location coincides with recorded sources of high-energy gamma rays identified by detectors including LHAASO in China, HAWC in Mexico, HESS in Namibia, and the Fermi satellite. These emissions reach individual photon energies exceeding 100 trillion electron volts (100 TeV), a level significantly higher than the capacity of the Large Hadron Collider.
Comparing Microblazars and Extragalactic Blazars
While both systems share the characteristic of a jet pointed toward the observer, they differ fundamentally in scale and power. Extragalactic blazars are powered by supermassive black holes with masses millions to billions of times that of the Sun. In contrast, IRAS 18293–0941 is driven by a stellar-mass black hole, providing astronomers with a rare, nearby laboratory to study the mechanics of relativistic jets. This proximity allows for detailed observations that were previously only possible for objects located at extreme distances across the universe.
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