Synopsis: Star chime could reveal small black holes

Smallish black holes left behind from the early universe might cause detectible vibrations as they pass through the sun or other stars.
Synopsis figure
M. Kesden and S. Hanasoge, Phys. Rev. Lett. (2011)

In theory, black holes come in all sizes, not just the star- and galaxy-scale objects that astronomers have already seen. In particular, smaller “primordial” black holes might have formed from density fluctuations in the first seconds after the big bang. In addition to providing a window into the universe in its earliest moments, these remnants could be the cold dark matter that makes up about a quarter of its present mass.

Previous observations rule out abundant black holes smaller than 10-16 or larger than 10-7 times the mass of the sun, but intermediate sizes could still account for cold dark matter. In Physical Review Letters, Michael Kesden at New York University and Shravan Hanasoge at Princeton University, New Jersey, propose that these medium-sized black holes could be detected when they pass through a star. Although the black hole will hardly be affected, it will leave lingering acoustic vibrations in the star, analogous to the ringing of a bell.

The hard part will be distinguishing this ringing from the ambient vibrations caused by turbulent fluid motion. But the researchers calculated that a black hole passing through a star like the sun excites modes with higher frequencies and larger spatial scales than turbulence does, making it easily noticeable. Unfortunately, the researchers also estimate that we would need millions of years to see such an event in our particular star. As an alternative, simultaneous but less detailed monitoring of many other stars could also reveal primordial black holes. – Don Monroe


Announcements

More Announcements »

Subject Areas

AstrophysicsCosmology

Previous Synopsis

Fluid Dynamics

Stop! Slippery water

Read More »

Next Synopsis

Superconductivity

Rare pressure

Read More »

Related Articles

Synopsis: Emptiness Constrains the Universe
Astrophysics

Synopsis: Emptiness Constrains the Universe

The distribution of galaxies around regions of relatively empty space can be used to constrain cosmological parameters. Read More »

Synopsis: A Relativistic View of a Clumpy Universe
Cosmology

Synopsis: A Relativistic View of a Clumpy Universe

Cosmologists have begun using fully relativistic models to understand the effects of inhomogeneous matter distribution on the evolution of the Universe. Read More »

Synopsis: Solar Cycle Affects Cosmic Ray Positrons
Astrophysics

Synopsis: Solar Cycle Affects Cosmic Ray Positrons

Discrepancies in the positron content of cosmic rays measured at different times are explained by the periodic reversal of the solar magnetic field’s direction. Read More »

More Articles