Astrophysicists discover universal rule for black hole jet eruptions

Astrophysicists have identified a universal rule governing when black holes launch powerful jets of matter, often referred to as cosmic ‘burps’. Research published in Nature Astronomy indicates that these eruptions occur when the accretion rate—the rate at which the black hole feeds—drops to 2% of the Eddington limit.

This threshold appears to be consistent across all black hole sizes, from stellar-mass objects to supermassive giants. Previously, scientists struggled to explain why some black holes emit jets immediately after consuming a star, while others remain dormant for months or years before erupting.

The study, co-led by Andrew Mummery of the Institute for Advanced Study and Adelle Goodwin of Curtin University, analyzed 20 tidal disruption events using radio telescopes. When a star is torn apart by tidal forces, roughly half of its material is swallowed, while the remainder is violently expelled in jets that can travel thousands of light-years and influence the evolution of entire galaxies.