Scientists have discovered the reason for the unusual behavior of neutron stars: emission from the liquid core

Austrian astrophysicists at the University of Innsbruck have conducted a study that reveals why a neutron star’s rotation suddenly accelerates, contrary to known laws of nature. As it turns out, this acceleration is associated with the amazing properties of the materials from which they are made. The research results were published in the journal Physical Review Letters (PRL).

Neutron stars are formed by the collapse of a massive star, during which the star’s core is compressed under the influence of gravity into an object about 20 kilometers in diameter. The matter inside such objects has an incredible density. A particle of this material on Earth is about the size of a sugar cube and weighs about 1 billion tons, which is equivalent to the weight of 150 of Egypt’s Great Pyramids. Because it is impossible to obtain material samples from neutron stars, scientists have used simulations to study the internal processes in the cores of extinct stars. Their study analyzed a mixture of cryogenic atoms of the rare earth metals erbium and dysprosium.

Calculations show that the material beneath the neutron star’s surface is in the form of a viscous, superfluid fluid that rotates in the form of many tiny vortices. At a certain point, the material can have the properties of a supersolid state and a superfluid state simultaneously. Vortices are thrown from the liquid core into the outer crystalline crust, greatly accelerating its rotation. Study author and astrophysicist Francesca Ferlaino said: “This study presents a new approach to understanding the behavior of neutron stars and opens new possibilities for quantum modeling of stars in low-energy laboratories on Earth. It’s something that opens up.”