The Life and Death of Stars That Capture Primordial Black Holes ✛ ✦
Context
The dark matter problem remains one of the central challenges in modern astrophysics. Stephen Hawking proposed that dark matter could consist of primordial black holes (PBHs) formed in the early universe. The asteroid-mass range ($10^{17}$–$10^{23}$ g) is particularly intriguing, as constraints there are weak. The capture of such PBHs by stars, including red dwarfs, opens a new way to detect them. The timescales are on the order of the Hubble time, discovered by Edwin Hubble.
Methods
The authors used a combination of analytics, stellar evolution models, and 3D simulations. Back in the mid-20th century, Subrahmanyan Chandrasekhar developed the theory of dynamical friction, applied here to calculate the braking of a PBH inside a star. Interaction with a giant planet (exoplanet) enables efficient PBH capture. The modeling covers the entire cycle, including a possible explosion akin to a supernova (but without a radioactive tail), and generation of gravitational waves from remnant mergers, which could be detected by LIGO.
Results
Capture is effective only with a third body—e.g., a giant planet. For a solar-type star with a Jupiter analog, the critical PBH mass for inspiral within its lifetime is about $10^{22}$ g. In the core, the PBH grows via quasi-spherical Bondi accretion at low efficiency. If enough angular momentum accumulates before the star is consumed, a disk forms. This transition occurs at a PBH mass of 0.01–1 M⊙, with spin reaching a* ≈ 0.8. Then, jets and winds launch, destroying the star in minutes. Monte Carlo modeling shows that roughly half of systems undergo the explosive scenario, while the rest end in quiet consumption. Explosive events can produce X-ray/gamma-ray flashes, a UV peak at ~1 day, and radio afterglow. Jet power could reach $10^{50}$ erg/s. These explosions may resemble low-luminosity gamma-ray bursts. Also predicted are gravitational-wave signals from mergers of substellar black holes—a potential target for LIGO.
Implications
The results show that stars with PBHs inside do not evolve monotonically but can end in a bright transient, providing a new class of predictions for observational astrophysics. This links dark matter physics, high-energy astrophysics, and gravitational-wave astronomy.
Future development
Future studies should compute detailed light curves and spectra of such explosions, and refine capture rates accounting for realistic distributions of planetary systems. It is important to investigate how often jets remain ultra-relativistic and pierce the envelope.
Impact
This discovery will impact dark matter searches, interpretation of rare transients (such as low-luminosity GRBs), and gravitational-wave surveys like LIGO.
Next steps
Next steps include modeling jet propagation through the envelopes of stars, computing population rates given the PBH mass function, and searching for candidates in archival transient data.
Key open problems
The work directly addresses unsolved problems: the nature of dark matter, mechanisms of core-collapse supernovae, and the origin of intermediate-mass black holes.
The knowledge machine's view
This section is addressed to the author of the paper and their colleagues. Neighbouring works were found by meaning-based search across our archive, not by word overlap. We do not review: we show the field around the work.
What the work does
For the first time, the authors model the complete evolutionary cycle of a star that captures a primordial black hole (PBH), from a three-body gravitational capture involving a giant planet to the PBH's migration into the core, accretion, and possible disk formation. Using analytical methods, stellar evolution models, and three-dimensional simulations, they show that the system's fate bifurcates: disk accretion produces jets and an explosion that destroys the star, while otherwise the star is quietly consumed. They estimate observational signatures: X-ray/gamma-ray flares, an ultraviolet peak, radio afterglow, and gravitational-wave signals from mergers of substellar black holes.
Where its strength is
This work connects dark matter physics, high-energy astrophysics, and gravitational-wave astronomy, offering a new class of predictions for observations. Particularly strong is the calculation of the transition from quasi-spherical Bondi accretion to disk accretion, with estimates of critical mass and spin, which allows distinguishing between explosive and quiet scenarios.
Where it could go next
- It might be interesting to compare the predicted explosive events with gamma-ray constraints on PBHs, as considered in the work on the traces of invisible black holes in gamma-ray light.based on: Invisible Black Holes Leave a Mark in Gamma-Ray Light arXiv:2606.13788
- A related study examines how tiny black holes could act as stellar detonators; perhaps their approach to modeling explosive energy release could apply to your scenario.based on: Dark Matter's Invisible Sparks: Tiny Black Holes as Stellar Detonators arXiv:2606.07505v2
- There is a paper in the archive on the influence of PBHs on the expansion rate of the Universe; it would be interesting to estimate how much your channel of PBH capture by stars changes cosmological evolution.based on: Cosmic Hot Tap: How Primordial Black Holes Rewrite the Speed of the Universe arXiv:2607.18528v1
Worth trying
- Check whether the predicted flares are consistent with existing gamma-ray observations, using constraints from work 2606.13788.
- Apply the stellar detonation model from work 2606.07505v2 to your case to refine the explosion energy and duration.
- Estimate the contribution of stars destroyed by PBHs to the background radiation and compare with limits on the cosmological PBH density from work 2607.18528v1.
Why this may matter
Such studies could provide a new way to search for dark matter in the form of PBHs through observations of transients and gravitational waves, and also link the microphysics of accretion to the global evolution of stellar populations.
Nearby works in our archive
- Dark Stars: Cradle of Giant Black Holessimilarity 0.69
- Cosmic Hot Tap: How Primordial Black Holes Rewrite the Speed of the Universesimilarity 0.68
- Dark Matter's Invisible Sparks: Tiny Black Holes as Stellar Detonatorssimilarity 0.67
- Dark Stars: First Light from Invisible Mattersimilarity 0.67
- Invisible Black Holes Leave a Mark in Gamma-Ray Lightsimilarity 0.66
- Tiny Black Holes Warm the Universe Longer Than Thoughtsimilarity 0.66
The closest work in the archive sits at 0.69 by meaning — the usual level for our corpus.
Original abstract
as written by the authors arXiv:2606.02700v1
Primordial black holes (PBHs) in the asteroid mass window ($$10^{17}-10^{23}\,{\rm g}$$) remain viable dark matter candidates and can be captured by stars. We develop the first global framework for the evolution of stars that capture PBHs, combining analytic calculations, stellar evolution models, 3D general-relativistic magnetohydrodynamic simulations, and Monte Carlo population synthesis. We find that the fate of these systems bifurcates: PBHs that form an accretion disk before consuming the host drive explosive disruption, whereas PBHs captured too late or growing too slowly consume the star quietly. Capture is dominated by three-body interactions with planetary or stellar companions. For a solar-type host with a Jupiter analog, inspiral within a main-sequence lifetime requires $$M_{\rm BH}^{\rm crit}\gtrsim 10^{22}\,{\rm g}$$, while lighter PBHs generally require tighter companions. Once deposited at the center, the PBH grows through inefficient quasi-spherical Bondi accretion; if it reaches the angular-momentum threshold before consuming the host, the inflow circularizes into a disk. Our Monte Carlo calculations yield sizable quiet-consumption and explosive-disruption populations, with final PBH masses $$M_{\rm BH}\sim0.01-1\,M_\odot$$ and disk-forming PBH spins $$a_\ast\approx0.8$$. Disk formation is the point of no return: disk winds and relativistic jets of $$\sim10^{45}-10^{50}\,{\rm erg\,s^{-1}}$$ disrupt the star within minutes. The resulting transients may include a $$\sim$$day-long UV/blue signal, radio afterglow, and, if the jet escapes, an X-ray-flash/low-luminosity gamma-ray-burst (XRF/llGRB) signal. For an $$O(1)$$ PBH dark matter fraction and optimistic capture assumptions, the event rate can reach that of llGRBs. The low-mass, high-spin remnants offer a complementary PBH probe and possible source for subsolar BH mergers.
If a primordial black hole of $10^{16}$ g were at the Sun's center, it would grow so slowly that it would only reach the disk stage after 10 billion years — roughly the age of our star. So our Sun could be a 'Hawking star' with no visible consequences... for now.
The idea of a star devoured from within by a microscopic black hole echoes Arthur C. Clarke's novel 'Rendezvous with Rama,' where an alien artifact uses a black hole as a power source. In the 2009 'Star Trek' film, red matter creates black holes inside planets, causing them to collapse.
Key numbers
- PBH mass window: 1017–1023 g
- critical mass for capture: ~1022 g
- PBH mass at disk formation: 0.01–1 M⊙
- spin at disk formation: ≈0.8
- maximum jet power: up to 1050 erg/s