Astronomers have identified IRAS 18293-0941 as the strongest candidate yet for a microblazar, a binary system located 12,000 light-years away in the Milky Way where a black hole orbits a massive star and fires relativistic jets of energy nearly directly toward Earth, Live Science reported.
Decades-Old Theoretical Object Found Inside the Milky Way
For decades, astrophysicists predicted the existence of microblazars. These systems act as scaled-down versions of distant blazars—supermassive black holes residing at the centers of galaxies that strip material from host stars and eject opposing particle beams close to the speed of light. When one of those relativistic jets points directly toward our planet, astronomers classify it as a blazar. Smaller binary equivalents within our own galaxy had long remained theoretical until an international team of researchers from Spain, the Netherlands, and Argentina described IRAS 18293-0941 in a study accepted for publication in the journal Astronomy and Astrophysics.
“It is the first time that we have a serious candidate,” Josep Martí, an astronomer at the University of Jaén in Spain and first author of the study, told Live Science.
The system was initially flagged back in 1983 when data captured by the Infrared Astronomical Satellite revealed an unidentified point source emitting high levels of infrared energy. Years of subsequent observations proved hindered by the object’s position behind dense clouds of dust along the plane of the Milky Way, as noted by BBC Sky at Night Magazine.
Orbital Dynamics and Relativistic Jets at Three-Quarters Light-Speed
IRAS 18293-0941 consists of a hot, gigantic star orbited by a stellar-mass black hole every 11.38 days, according to reporting by the Oregon Coast Beach Connection. As the two objects interact, matter is pulled from the star and accreted into a disk around the black hole. While much of that material falls past the event horizon, a fraction is redirected into two opposing beams launched outward at approximately three-quarters the speed of light.
One of these plasma jets is aimed almost directly at Earth. The opposing jet points 180 degrees in the other direction. Because astronomers cannot directly view the jet facing away from us, they confirmed its existence by identifying a glowing hotspot where the high-speed plasma slams into the surrounding interstellar medium, heating ambient gas and dust.
Catching these objects requires precise timing. “Because of stellar evolution, you need to catch the system at the right time,” Martí explained to Live Science, noting that the active microquasar phase is exceptionally brief.
Instruments Used and Missing Characteristics
To capture and verify the data on IRAS 18293-0941, the research team deployed a multi-instrument approach. Observations relied on the Calar Alto Astronomical Observatory in Spain, the European VLBI Network, the MeerKAT radio telescope array in South Africa, and archival data sourced from the Very Large Array in New Mexico.
The system displayed nearly all expected microblazar signatures, including broad electromagnetic spectrum emissions and an opposing interstellar hotspot. However, it lacked one predicted feature: rapid variability. Typical microblazars exhibit sharp, frequent changes in brightness amplified by Doppler boosting because their jet faces Earth. Martí stated that the dense cloud of gas enveloping IRAS 18293-0941 likely dampens those quick fluctuations, smoothing out the optical profile.
Independent researchers have expressed confidence in the findings. Kinwah Wu, a theoretical astrophysicist at University College London, told Live Science via email that the claims are sensible and free of questionable assumptions, noting clear signatures of particle interactions between the jets and ambient material.
