An international team of scientists, led by researchers from the University of East Anglia, in the United Kingdom, found an asymmetric double-neutron star system using the powerful Arecibo radio telescope.
This type of star system is believed to be it is a precursor to the fusion of double neutron star systems such as the one discovered by LIGO (Laser Interferometer Gravitational-Wave Observatory in the United States) in 2017.
LIGO's observation was important as it confirmed that gravitational waves they are associated with neutron star fusion.
The work published by this team yesterday in the journal Nature indicates that these types of double neutron star systems may be the key to understanding dead star collisions and the expansion of the universe.
"In 2017, LIGO scientists first detected the fusion of two neutron stars," said physicist Robert Ferdman, who led the team.
He added that “the event caused gravitational waves through space time, as Albert Einstein predicted more than a century ago. He confirmed that the phenomenon of short gamma-ray bursts was due to the fusion of two neutron stars. ”
One of the unique aspects of the 2017 discovery and today's discovery is that the observed double neutron systems are made up of stars that have different masses.
Current theories about the 2017 discoveries are based on the fact that the masses of stars are equal to or very close in size.
“The double neutron star system that we observe shows the most asymmetric masses among those of known fusion systems within the age of the universe, "said Benetege Perera, scientist at the Arecibo Observatory and who was co-author of the publication.
He argued that" based on what we know about LIGO and our study, the Understanding and characterizing the population of double asymmetric mass neutron stars is vital to gravitational wave astronomy. ”
Perera, whose research is c enters pulsars and gravitational waves, joined the NSF-funded Arecibo Observatory in June 2019.
The facility, which is managed by the University of Central Florida, through a cooperation agreement with the NSF offers scientists around the world a unique look at space due to its specialized instruments and its location near the equator.
The team discovered an unusual pulsar, one of the types of magnetized neutron stars in deep space that they emit highly focused radio waves from their magnetic poles.
The newly discovered pulsar (known as PSR J1913 + 1102) is part of a binary system – meaning it is locked in a very narrow orbit with another neutron star.  "The Arecibo Observatory has a long legacy of discoveries of important pulsars," said NSF program officer Ashley Zauderer.
For the expert, "this emotion This result shows how incredibly relevant the unique sensitivity of the Arecibo radio telescope is to scientific research in the new era of astrophysics. ”
Neutron stars are the dead stellar remnants of a supernova explosion. They are made up of the densest known matter, containing hundreds of thousands of times the mass of Earth in a sphere the size of a city like New York.
In about 500 million years the two neutron stars will collide, releasing staggering amounts of energy in the form of gravitational waves and light.
“That collision is what the LIGO team observed in 2017. The event was not surprising, but the sheer amount of matter ejected from the fusion and its brilliance was unexpected. Ferdman said.
He added that "most theories about this event assumed that neutron stars locked in binary systems are very similar in mass. But this newly discovered binary is unusual, because the masses of its two neutron stars are quite different, with one much larger than the other. This discovery changes the assumptions previously made. ”
This asymmetric system gives scientists confidence that double mergers of neutron stars provide vital clues to the unsolved mysteries in astrophysics, including a more precise determination of the rate of the universe's expansion, known as the Hubble constant.
Perera has multiple degrees, including a Ph.D. in physics from the University of West Virginia.
He authored and co-authored dozens of journal articles recognized and featured in conferences around the world. He previously taught at the University of Manchester and was a summer fellow at Purdue University.