Tiny black holes may trigger stellar explosions across Milky Way

Primordial black holes may trigger white dwarf stars to explode as Type Ia supernovae, according to a study published on August 1, 2026, in The Astrophysical Journal.

These objects, hypothetical remnants from the universe’s earliest moments, are a candidate for dark matter, which accounts for about 90 percent of all matter by mass.

Led by Shing-Chi Leung of SUNY Polytechnic Institute and the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), with Ken’ichi Nomoto and Alexander Kusenko, the research team modeled a black hole traversing a white dwarf. The gravitational tidal forces would destabilize the star, sparking a thermonuclear runaway.

Simulations reproduced the observed properties of supernova remnants Tycho, Kepler, and 3C 397, as well as nearby events SN 2011fe and SN 2012cg.

Examining radioactive isotopes such as nickel-56 and nickel-57, the researchers inferred that a non-zero fraction of Type Ia supernovae may need primordial black hole triggers to explain chemical abundance trends seen in Milky Way stars.

A 2025 paper by the same group first demonstrated that such explosions could mimic standard Type Ia models. The new work strengthens the case by matching both supernova data and stellar abundances.

Leung noted that indirect clues to the properties of these elusive objects can be gleaned from their supernova influence. The team plans to explore how PBH-triggered events affect the overall population and rates of conventional supernovae.