New form of matter in neutron stars may explain pulsar spin rates

Space.com : Pulsars are rapidly spinning neutron stars —extremely dense cores of massive stars that have undergone supernova explosions. One interesting characteristic of pulsars is that none are known to spin more slowly than 1 revolution every 12 seconds. José Pons of Alicante University in Spain and his colleagues have proposed that a new form of matter may explain why. The theoretical matter, called nuclear pasta, occurs when particles are packed together so tightly that they form sheets and curls similar to the shapes of pasta. Pons’s team believes that the presence of such structures increases the electrical resistivity of the star. Hence, electrons move through the star more slowly, which allows the star’s magnetic field to dissipate more rapidly. Electromagnetic radiation emitted by the star is considered one of the factors that slows its rotation. But if the strength of the star’s electromagnetic field is already reduced because of the pasta structures, the pulsar could not slow beyond a certain minimum rotation speed.