Along with black holes, neutron stars are the result of stars collapsing under gravity once their fuel burns out, until their density is about the same as that of the nucleus of an atom, at which point the protons and electrons “melt” into pure neutrons. Just how dense are we talking? If you had a piece of neutron star the size of a mere sugar cube, it would weigh a whopping 100 million tons. Only black holes are denser.
Scientists suspect that something akin to a quark-gluon plasma may lie at the innermost core, while more conventional matter comprises the outermost edges of the star. In between, making up the crust, is a rare state of degenerate matter known as “nuclear pasta” (made up not just of neutrons, but also protons and electrons). And the various shapes such “pasta” takes represent a series of phase transitions as this boundary layer goes from lumpy to smooth.
At a press conference of the APS April Meeting this past weekend in Baltimore, Maryland, Indiana University graduate student Matt Caplan gave an overview of the ongoing work in Charles Horowitz’s lab, running intricate computer simulations of various types of nuclear pasta to calculate the respective properties, in hopes of learning more about the evolution of neutron stars. It has to be simulated, because the rare conditions necessary for the pasta to form can really only be found in the cores of neutron stars.
To read more, click here.