Pulsar discovery may solve mystery of strange neutron star crashes - Space.com

A better understanding of neutron star mergers could shed light on the origins of the universe's heaviest elements.

However, until now, the nine known binary systems composed of neutron stars orbiting each other closely enough to merge within the age of the universe all involved pairs of roughly equal mass.

Now scientists have found a binary composed of neutron stars of different sizes, which supports the possibility that GW170817 was a merger between such neutron stars.

PSR J1913+1102 is part of a binary system with another neutron star.

This is the most unequal pairing seen yet between neutron star binaries that will likely one day merge.

"This is the first system we've found of its kind — a double neutron star binary system in which the relative masses of the two neutron stars in the system are so significantly different," study lead author Robert Ferdman, an astrophysicist at the University of East Anglia in England, told Space.com.

All in all, asymmetric binaries could make up about 10% of all merging neutron star binaries, Ferdman said.

Since asymmetric neutron star mergers may often lead larger neutron stars to warp smaller companions, investigating such unequal partnerships may help researchers "delve deeper into understanding what makes up a neutron star," Ferdman said.

"What sort of matter makes up the interior of a neutron star is quite a mystery, so observing the distortions a neutron star undergoes might help us understand them better.".

In addition, the researchers noted that gravitational merging neutron stars might help shed light on a cosmic mystery concerning how quickly the universe is expanding.

Asymmetric neutron star mergers that produce detectable gravitational and electromagnetic signatures could lead to very precise measurements of the Hubble constant and help solve the so-called Hubble constant conflict, Ferdman noted.

In the future, the researchers want to find more of these asymmetric neutron star binaries "to get an even better idea of how common they are," Ferdman said.