The team behind a new paper in The Astrophysical Journal has a claim that sounds like it belongs in a lecture hall: some of the exploding stars you can see in the sky may have been set off by black holes left over from the first moments of the universe.
Not black holes formed from dying stars. Older ones. Hypothetical ones. And the argument isn’t hand-waving, because the researchers went looking for fingerprints in things we’ve already measured.
What a primordial black hole is supposed to be
Primordial black holes, or PBH, are proposed leftovers from the universe’s earliest moments. The thinking is that they formed during cosmic inflation, when rapid expansion amplified small fluctuations in how matter was distributed.
They’ve also been floated as candidates for dark matter, the invisible material believed to make up about 90% of all matter in the Universe by mass. You can’t see dark matter directly. But its gravitational effects turn up throughout galaxies and across the wider cosmos.
The part where a black hole walks through a star
Here’s the mechanism. Primordial black holes could pass through stars as they travel across the universe. Earlier work suggested that if one went through a white dwarf, its gravity would generate powerful tidal forces inside the star.
Those forces might destabilize the white dwarf badly enough to make it explode as a Type Ia supernova.
A white dwarf is the dense remnant left behind after a low-mass star burns through its fuel. Type Ia supernovae are the extremely bright explosions generally thought to happen when a white dwarf becomes unstable and runs away into a thermonuclear reaction. The standard story doesn’t involve a black hole at all, which is what makes this alternative route worth testing rather than assuming.
They checked it against supernovae we’ve already seen
The research was led by Shing-Chi Leung, an assistant professor at SUNY Polytechnic Institute and a visiting associate scientist at The University of Tokyo Kavli Institute for the Physics and Mathematics of the Universe. The team also included Visiting Senior Scientist Ken’ichi Nomoto and Senior Fellow Alexander Kusenko.
The group looked at the motion, brightness and chemical properties of supernovae produced through this proposed explosion channel. In an earlier paper published in 2025, they had already shown that PBH-triggered explosions could produce Type Ia supernovae with properties closely resembling those from standard models.
For the new study they went further and compared their models against real objects: the well known remnants Tycho, Kepler and 3C 397, nearby supernovae including SN 2011fe and SN 2012cg, and the chemical abundances of Milky Way stars.
The models reproduced several characteristics seen in those supernovae and their remnants.
The chemistry is where it gets specific
The researchers examined radioactive isotopes such as Ni-56 and Ni-57, plus stable elements including Mn and Ni. Those signatures let them estimate the masses and metallicities of the stars that produced the explosions.
Metallicity, the amount of metal present when a star forms, probes when the star was born in the cosmic age. It offers clues about the chemical conditions that existed at that point in the history of the universe. In astronomy, metals means elements heavier than hydrogen and helium.
Supernovae throw newly formed elements into space, and that material can end up inside later stars and planets. So the team used their models to ask how much this explosion mechanism might contribute to galactic chemical enrichment.
The analysis indicated that a non-zero fraction of PBH-triggered Type Ia supernovae may be needed to explain the chemical abundance trend observed in stars across the Milky Way. Read that carefully. Non-zero is a modest word doing heavy lifting, and it stops well short of saying most or even many.
Still, the implication is that primordial black holes may have shaped our galaxy’s chemical evolution through the explosions they set off.
What the lead author will and won’t claim
"Our work suggests that some supernova that we observe in the sky could be a result of the PBHs. Therefore, even though we cannot directly observe these evasive entities, they leave many interesting clues in nature for us to probe their properties," Leung said.
That’s the honest framing. Nobody has caught a primordial black hole. What this work offers is a way to look for one indirectly, using explosions and leftover elements as the trail.
Next, the team plans to widen the investigation to how PBH-triggered explosions might affect the overall population of conventional supernovae and the combined rates of these brief but powerful events.
If you want a single number to hold onto from this study, make it the one in the abundance trend. The Milky Way’s stars carry a chemical pattern that standard supernova models don’t fully account for, and the proposed fix is a population of explosions nobody has confirmed exists.
