Neutron Stars Spin 716 Times/Second

How can an object more massive than our sun spin faster than a kitchen blender? The answer lies in its violent birth and a fundamental law of physics. Neutron stars are the ultra-dense collapsed cores left behind after a massive star explodes in a supernova. As the star's enormous core crushes down from millions of miles across to a sphere just a dozen miles in diameter, it must conserve angular momentum. This is the same principle that causes an ice skater to spin faster when they pull their arms in. The star's initially slow rotation is amplified to incredible speeds, while its matter is compressed so tightly that its gravity becomes one of the strongest forces in the universe.

We observe these rapidly spinning stellar remnants as "pulsars." As a neutron star rotates, it emits powerful beams of radiation from its magnetic poles. If these beams happen to be oriented correctly, they sweep across Earth like a cosmic lighthouse beam, and our radio telescopes detect a regular "pulse." For the pulsar PSR J1748-2446ad, this pulse arrives an astonishing 716 times every second. This rotation is so extreme that it is pushing the theoretical limits of physics; any faster, and the immense gravitational force holding the star together would likely be overcome by the centrifugal force tearing it apart.