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Heaviest Neutron Star
Astronomers are always trying to weigh the stars. That’s because precise measurements of a star’s mass can reveal what’s happening inside it. And that applies to dead stars as well as live ones.
A recent study, for example, reported the discovery of the heaviest neutron star yet seen. It could rule out some models of how such stars behave, but open up some others.
A neutron star is the corpse of a once-mighty star. When the star’s core can no longer produce nuclear reactions, it collapses, forming a neutron star. The star is heavier than the Sun, but no more than 15 or 20 miles in diameter. That makes it extremely dense — the densest form of matter in the universe.
Yet scientists aren’t sure just what form that matter takes. It could be a form that’s a bit “squishy,” or other forms that are stiffer. The new discovery could narrow down those ideas.
Scientists used radio telescopes to measure a binary system that contains a neutron star and another type of stellar corpse. The neutron star is also a pulsar. It spins about 350 times per second, emitting a “pulse” of energy with each turn. The gravity of its companion, though, produces tiny changes in the timing of those pulses.
Astronomers timed the pulses for more than a dozen years. And they found that the neutron star is about 2.14 times the mass of the Sun. That gives scientists something to think about as they ponder the interiors of these odd stellar corpses.