“Nuclear Pasta” in Neutron Stars Penetrates Deeper Than Expected

Researchers have discovered that the strange nuclear shapes known as “nuclear pasta” penetrate deeper into the cores of neutron stars than previously thought. Neutron stars are the remnants of massive stars, with densities so extreme that atomic and nuclear bonds are broken, creating a sea of free-floating neutrons, electrons, and protons. It is believed that the cores of neutron stars consist of a dense semi-liquid of quarks, the fundamental constituent of matter.

A pair of theoretical physicists have examined the transition zone between the quark core and the neutron outer layers of neutron stars, using the latest models of quark and neutron behavior. They discovered that the “nuclear pasta,” which consists of compact clumps of neutrons immersed in a sea of quarks, can reach deeper into the quark core due to the favorable effects of curvature tension. Tubes and bubbles can survive to higher densities, while drops and rods do not last for long.

This finding has significant implications for kilonova explosions, which occur when neutron stars collide. The details of these explosions, including their ability to produce heavier elements on the periodic table, depend on the internal structures of neutron stars. Differences in the depth and shape of the neutron structures can affect how these explosions evolve.

Further research is needed to explore how kilonova explosions can provide insights into the detailed structures of neutron star interiors. The study of “nuclear pasta” and its impact on the properties of neutron stars contributes to our understanding of these extreme cosmic objects.

Source: *Physics World*