JUL 11, 2021 5:40 AM PDT

A Black Hole-Neutron Star Merger Makes Waves

WRITTEN BY: Carmen Leitch

Researchers have found evidence of two mergers of black holes and their companion neutron stars that were about 900 million light-years away from Earth. The gravitational ways generated by these events hit Earth in January 2020. The black hole-neutron star mergers are though to be the first ever reliably detected, and they occurred only ten days apart from each other. This work, which was reported in the Astrophysical Journal Letters, can help scientists learn more about how these rare binary systems emerge.

An artistic image inspired by a black hole-neutron star merger event./ Credit: Carl Knox, OzGrav/Swinburne

"Gravitational waves have allowed us to detect collisions of pairs of black holes and pairs of neutron stars, but the mixed collision of a black hole with a neutron star has been the elusive missing piece of the family picture of compact object mergers," said study co-author Chase Kimball.

The two new gravitational-wave events were called GW200105 and GW200115. They were identified on January 5, 2020, and January 15, 2020 and were observed by LIGO and Virgo detectors.

One LIGO detector picked up on the signal from GW200105 while the other LIGO detector was offline, and the signal was not picked up by Virgo. Gravitational wave data suggested that a 9-solar mass black hole had merged with an object that was almost 2-solar masses. The collision happened about 900 million light-years away from us.

Ten days later, both LIGO instruments and the Virgo instrument detected GW200115, which was produced when a 6-solar mass black hole merged with a 1.5-solar mass neutron star, around 1 billion light-years from our planet.

These two events are the first reliable observations of neutron star-black hole mergers. Researchers may now be able to estimate how often they happen. Right now, it's thought that within about one billion light years of us, about one merger happens every month. Scientists are still learning where binary systems like this come from.

"We've now seen the first examples of black holes merging with neutron stars, so we know that they're out there," said Maya Fishbach, Ph.D., a NASA Einstein Postdoctoral Fellow. "But there's still so much we don't know about neutron stars and black holes: how small or big they can get, how fast they can spin, how they pair off into merger partners. With future gravitational wave data, we will have the statistics to answer these questions, and ultimately learn how the most extreme objects in our universe are made."

Sources: AAAS/Eurekalert! via Northwestern University, Astrophysical Journal Letters

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JUL 04, 2021
Space & Astronomy
After the Big Bang Came the Cosmic Dawn
JUL 04, 2021
After the Big Bang Came the Cosmic Dawn
It's been estimated that the universe began about 13.8 billion years ago in a violent explosion known as the Big Bang. R ...
JUL 15, 2021
Space & Astronomy
Modern Slavery in Greece Spotted from Space
JUL 15, 2021
Modern Slavery in Greece Spotted from Space
Migrant settlements being exploited for work have been spotted with satellite imagery by researchers led by the Universi ...
JUL 22, 2021
Space & Astronomy
On Mars, the Perseverance Rover is Set to Acquire Its First Sample
JUL 22, 2021
On Mars, the Perseverance Rover is Set to Acquire Its First Sample
One of the special features of NASA's Perseverance Rover is its ability to perform some scientific experiments. One of i ...
JUL 26, 2021
Space & Astronomy
A Moon-Forming Disc is Observed Surrounding an Exoplanet
JUL 26, 2021
A Moon-Forming Disc is Observed Surrounding an Exoplanet
Researchers have been able to detect a disc surrounding an exoplanet called PDS 70c with the Atacama Large Millimeter/su ...
JUL 29, 2021
Space & Astronomy
Hubble Spots Evidence of Water on Jupiter's Moon
JUL 29, 2021
Hubble Spots Evidence of Water on Jupiter's Moon
Scientists have spotted evidence of water vapor in the atmosphere of Jupiter's moon, Ganymede. The corresponding stu ...
JAN 17, 2022
Cell & Molecular Biology
'Space Anemia' is Due to an Accelerated Loss of Red Blood Cells
JAN 17, 2022
'Space Anemia' is Due to an Accelerated Loss of Red Blood Cells
When astronauts go to space, many of them become anemic; they lose red blood cells. It's been suggested that space anemi ...
Loading Comments...