New heavyweight champion overturns exotic theories
Astronomers have weighed a neutron star with nearly double the mass of the sun, the heaviest yet found. A mass that high rules out many theories that these ultradense remnants of supernova explosions contain anything other than ordinary matter, researchers report in the Oct. 28 Nature.
Some theorists have suggested that the high pressure in a neutron star’s core could break the matter there down into a soup of unbound quarks, the subatomic particles that combine to make protons and neutrons, or other exotic forms.
But that’s not a likely scenario if neutron stars as heavy as this one exist, says Coleman Miller, an astrophysicist at the University of Maryland in College Park who was not involved in the research. In most theoretical models, a quark star should collapse into a black hole before it ever reached two solar masses. Ergo, neutrons probably remain neutrons even under high pressure.