Scientists May Soon Detect Exotic Matter Inside Neutron Stars

Gravitational waves from merging neutron stars could reveal the presence of a quark-gluon plasma.

Mar. 15, 2026 at 10:00am

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Researchers have developed a new theoretical model that could allow scientists to 'see' inside neutron stars and detect the presence of a quark-gluon plasma - a state of matter that last existed just after the Big Bang. By analyzing the oscillations and gravitational waves emitted by binary neutron star systems, the researchers believe they can decipher the interior structure of these ultra-dense stellar remnants.

Why it matters

Understanding the interior of neutron stars could provide valuable insights into the fundamental nature of matter under extreme conditions. The possible existence of a quark-gluon plasma within neutron stars would shed light on the state of the universe in its earliest moments after the Big Bang. Deciphering the internal structure of neutron stars is also crucial for testing our theories of gravity and the behavior of matter at the most extreme densities found in the cosmos.

The details

Neutron stars are incredibly dense, with a mass several times that of the Sun packed into a sphere only about 20 kilometers across. The extreme pressure inside these stellar remnants can crush atoms apart, forming a 'soup' of neutrons. But deeper down, the pressure may be high enough to break apart the neutrons themselves, forming a quark-gluon plasma - a state of matter that last existed in the first fraction of a second after the Big Bang. To detect this exotic state of matter, researchers plan to analyze the gravitational waves emitted by binary neutron star systems as they spiral inward and merge. The oscillations and deformations of the neutron stars caused by tidal forces will imprint a characteristic 'signature' on the gravitational waves, which scientists can then use to infer the interior structure of the stars.

  • The research was published on February 18, 2026 in the journal Physical Review Letters.

The players

Nicolás Yunes

A professor at the University of Illinois who led the research team.

Abhishek Hegade

A researcher at Princeton University who co-authored the study.

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What they’re saying

“One hope is that we'll be able to get some information about the neutron-star equation of state at densities found in the inner core of a neutron star. Is there really a quark core, as some have recently claimed? Are there phase transitions occurring inside that we don't know about yet?”

— Nicolás Yunes, Professor, University of Illinois (Space.com)

“As they get closer, tidal forces from one [neutron] star begin to deform the other and vice versa. The amount of deformation depends on what's inside of those stars.”

— Abhishek Hegade, Researcher, Princeton University (Space.com)

What’s next

The researchers' theoretical work still needs to be validated by observational data from the next generation of gravitational wave detectors, which are expected to have the sensitivity required to detect the imprint of neutron star oscillations on the gravitational waves emitted by merging binary systems.

The takeaway

Deciphering the interior structure of neutron stars could provide a unique window into the fundamental nature of matter under the most extreme conditions found in the universe, potentially revealing the existence of a quark-gluon plasma - a state of matter that last existed just after the Big Bang.