NASA's IXPE Reveals Neutron Stars Have Solid Crusts and Superfluid Cores

New findings from NASA's Imaging X-ray Polarimetry Explorer (IXPE) have confirmed that neutron stars possess a solid outer crust. These ultra-dense remnants of exploded stars also contain a superfluid core, offering fresh insights into extreme physics. The discoveries could even pave the way for future technologies inspired by superfluidity.

Neutron stars form when massive stars collapse and explode in supernovae. What remains is an object so dense that a teaspoon of its material would weigh billions of tonnes. Their surfaces are nearly perfect spheres, shaped by crushing gravity.

NASA's IXPE has now studied four well-known neutron stars: 4U 0142+61, RX J1856.5-3754, Cassiopeia A, and Vela. Observations revealed strong linear polarisation, confirming their slightly flattened shapes and complex magnetic fields. Cassiopeia A, in particular, showed a dominant toroidal field deep inside, reshaping our understanding of their internal structures.

Beneath the solid crust—made of tightly packed neutrons, protons, and electrons—lies a core in a superfluid state. This frictionless fluid may explain how neutron stars maintain stability while influencing their magnetic and thermal behaviour. Such extreme conditions create a natural laboratory for testing fundamental physics.

Researchers believe these discoveries could inspire new technologies. Superfluidity, for instance, might lead to advancements in energy transfer or quantum computing. Further missions and observations are already planned to explore these cosmic objects in even greater detail.

The latest IXPE findings confirm that neutron stars have both a rigid crust and a frictionless superfluid core. These discoveries not only deepen our grasp of extreme physics but also open doors for potential technological applications. Upcoming studies will continue to unravel the mysteries of these extraordinary stellar remnants.