For the first time ever, scientists believe they have observed a black hole devouring a neutron star. It was such a catastrophic cosmic event that it sparked a ripple in space and time that finally reached Earth last week, some 900 million years after the black hole obliterated the neutron star.
Scientists are 99% sure that a black hole swallowed a neutron star some 900 million light-years away from Earth. On August 14, 2019, the gravitational waves from that celestial phenomenon finally reached our planet and were detected by American and Italian scientists.
A gravitational wave called S190814bv was detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO), which is composed of identical detector sites in Hanford, Washington, and Livingston, Louisiana; and its sister observatory called “Virgo,” a facility in Santo Stefano a Macerata, Italy, near the city of Pisa. These observatories are able to detect ripples in the fabric of the universe.
LIGO, which is operated by Caltech and MIT, detected the event. The Australian National University (ANU), which participated in the research of the “cataclysmic event,” believes it could be a “neutron star-black hole binary.”
Both neutron stars and black holes are two of the strongest forces in the universe and are both the results of a massive star dying. Massive stars often suffer a violent death, when a massive star collapses on its self, it creates a supernova explosion that spreads energy and cosmic matter into space, leaving a glowing ring of gas called a nebula.
After the explosion of a star that has as much as three times the mass of our sun, a neutron star can be born, which is a super dense star made primarily of neutrons and only about the size of a city, about 12 miles in diameter.
Conversely, sometimes when a gigantic star that is at least five times the mass of our sun and it explodes, it creates a black hole because the core contracts with such power that it swallows the space and anything else around them.
So it is rare to have these two very different byproducts of star deaths very close to one another. The black hole was large enough to consume an unimaginably dense neutron star. Neutron stars are so incredibly dense that just one teaspoon of neutron star material would weigh about 10 million tons.
Humans have only been able to detect gravitational waves since 2016 and all of the gravitational waves that have been detected since then have been because of black holes swallowing other black holes or collisions between neutron stars, but never a combination.
When two neutron stars collide, the collision emits a lot of light. In previous neutron star collisions, scientists could use gravitational waves and light to prove the collision. Gravitational wave S190814bv only has the gravitation wave and not light, prompting scientists to conclude that a black hole swallowed a neutron star.
Astronomers will be scanning the sky in the coming weeks to see if there is any fallout from the cosmic event, such as the black hole spilling out radiation after devouring the neutron star.
“We’ve never detected a neutron star and a black hole together,” said Ryan Foley, an astronomer at UC Santa Cruz, in a phone call. “If it turns out to be right, then we’ve confirmed a new type of star system. It’s that fundamental.”
The black hole would eat away at the neutron star or devour the entire neutron star. “About 900 million years ago, this black hole ate a very dense star, known as a neutron star, like Pac-man — possibly snuffing out the star instantly,” said Professor Susan Scott, leader of the General Relativity Theory and Data Analysis Group at ANU and a chief investigator with the Australian Research Council’s Centre of Excellence for Gravitational Wave Discovery (OzGrav).
“Scientists have never detected a black hole smaller than five solar masses or a neutron star larger than about 2.5 times the mass of our Sun,” said Professor Scott. “Based on this experience, we’re very confident that we’ve just detected a black hole gobbling up a neutron star.”
If this event is confirmed, it would be the first neutron star-black hole merger ever detected. Tou can read more space news HERE.