Primordial Black Hole Inside Star Could Survive via Dark Matter
A black hole weighing as little as a small car would, according to Stephen Hawking’s 1974 theory, evaporate almost instantly through Hawking radiation. Yet a new line of thinking suggests such a black hole could survive for billions of years inside a star’s core if it feeds on dark matter, gaining energy faster than it loses it.
The idea begins with a contradiction. Hawking’s radiation dictates that a black hole of about 40 tons would shine so brightly it would vanish in a flash — a timescale far too short to explain anything we observe today. To find one now, researchers would need to overturn a foundational assumption about how black holes interact with their environment.
The proposed solution involves dark matter, the invisible substance that makes up most of the universe’s mass. A black hole feeding on dark matter could gain energy faster than it loses it through Hawking radiation, a delicate balance that would allow the black hole to persist for eons.
When Gravity Meets a Quantum Trick
The story starts with a concept that sounds almost paradoxical. Hawking showed that black holes leak energy — the smaller the black hole, the quicker this leakage occurs.
A 40-ton black hole presents a particular puzzle: its evaporation would be so rapid that its lifetime would be incredibly brief, making the prospect of finding one today seem nearly impossible unless something intervenes.
That something could be dark matter particles swirling around the black hole. As the black hole consumes this matter, it gains mass and energy, counteracting the losses from Hawking radiation and stabilizing the black hole.
A Star’s Hidden Passenger Changes Everything
If such a black hole existed, it would likely reside within a star, perhaps one much larger than our Sun. The gravitational pull of the black hole would cause the star to wobble in a detectable pattern.
This is where the theory gets its most concrete foothold. A star with a 40-ton black hole at its center would exhibit a telltale signature: its surface would pulsate in a specific rhythm, a kind of stellar heartbeat that astronomers could measure.
This pulsation is not random — it is a direct consequence of the black hole’s presence and its interaction with the star’s material. The star would also appear unusually dim for its mass, as the black hole would consume some of the energy that would otherwise radiate outward.
The Hunt for a Quantum Relic
The research points toward a specific and testable outcome: a star harboring such a black hole would look different from a normal star, and its unique pulsation pattern is the key observable feature that could confirm this theory.
This finding connects to a larger quest in physics. Scientists are trying to understand whether primordial black holes — formed in the chaotic first moments of the universe — could still exist, and some theories suggest dark matter itself could be made of these ancient objects.
The work represents a bridge between the quantum world of Hawking radiation and the grand scale of stellar astronomy. It suggests that the smallest black holes might leave their most visible mark not in isolation, but by influencing the life of a star — a measurable pulsation that could finally reveal one of the universe’s most elusive inhabitants.