By Ron Cowen
When it comes to lying about their ages, certain stars are masters of spin. The stellar deception could throw into disarray theories describing some of the densest objects in the universe.
That’s the lesson two astronomers say they’ve learned from studying a seemingly young pulsar, the rapidly rotating corpse of a massive star. Left over from a supernova explosion, a pulsar crams as much mass as the sun into a sphere only 20 kilometers wide. The resulting pressure squeezes its electrically charged building blocks—electrons and protons—into a superdense ball of neutrons.