Gravitational Ringing Unveils Neutron Star Mysteries ⚡ экспресс
Gravitational waves from neutron star mergers let us peek into their interiors, where densities are many times higher than nuclear density. In a new study, scientists simulated such mergers with different equations of state (which describe the pressure-density relationship) and found a clear link: the ratio of energy loss to angular momentum in the long ringdown—the gradually fading signal after the merger—correlates with the properties of matter in the core. This pattern resembles how the fading ring of a bell reveals its material. It will help pin down the equation of state at supra-nuclear densities, where we have no direct access yet.
When a pair of neutron stars merge, gamma rays flash and ripples spread through spacetime—like striking a deep, resonant gong. The remnant keeps vibrating, emitting a fading gravitational ring.
Researchers simulated hundreds of these cataclysms, tweaking the elasticity of ultra-dense matter. It turned out that the ratio of lost energy to the drop in rotation speed uniquely determines how pliable the stuff is: rapid damping of the ring at the same spin-down rate signals a soft interior, much like a bell made of clay falls silent faster than a steel one. Funny thing, but at the star’s center matter is simultaneously superfluid and billions of times stiffer than any metal—this paradox makes the ringing even more revealing.
Peering into such depths used to be impossible. Now, by catching the gravitational echo with detectors pioneered by Rainer Weiss, we can directly learn what hides inside the most extreme "building blocks" of the cosmos. It will also hint whether black holes are born in these mergers and where Earth’s gold and platinum came from. By the way, the first neutron star as a pulsar was discovered by Jocelyn Bell Burnell in 1967—her find still springs surprises.
🎯 Some neutron stars spin at 716 times per second—faster than a kitchen blender.