'Black Widow' Is Heaviest-known Neutron Star
2022-08-07
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1Space scientists have observed what they believe is the most massive known example of an object called a neutron star.
2It has been called a "black widow" since it gained much of its mass by taking it from another star which it orbits.
3The star recently discovered by astronomers turns more than seven hundred times every second.
4Its mass is 2.35 times greater than our sun.
5The researchers said the star is close to the highest possible mass for an object of its kind.
6If it were any more massive it would collapse into a massive black hole.
7The researchers published their findings recently in Astrophysical Journal Letters.
8A neutron star is the dense, collapsed center, or core, of a massive star that exploded in an event called a supernova.
9This neutron star is a kind that is highly magnetized, called a pulsar.
10From Earth, pulsars appear to give off light repeatedly in short moments, like a lighthouse.
11Only one other neutron star is known to turn more quickly.
12Roger Romani is director of Stanford University's Center for Space Science and Astrophysics in the U.S. state of California. He helped write the research.
13Romani said, "The heavier the neutron star, the denser the material in its core."
14Romani added, "So as the heaviest neutron star known, this object presents the densest material in the observable universe.
15If it was any heavier it should collapse to a black hole, and then the stuff inside would be behind the event horizon, forever sealed off from any observation."
16Scientists use the term "event horizon" to describe a point close to a black hole beyond which nothing can escape including light.
17Romani said, "Since we don't yet know how matter works at these densities, the existence of this neutron star is an important probe of these physical extremes."
18The star is officially known as PSR J0952-0607.
19It is about 20,000 light years from Earth.
20A light year is the distance light travels in a year.
21The researchers studied it using the Keck I telescope in the state of Hawaii.
22Stars that are about eight or more times the sun's mass change the chemical hydrogen into heavier elements.
23When they build up about 1.4 times the mass of our sun in the element iron, their core collapses into a neutron star.
24A neutron star is very small-about the size of a city.
25But within that small area, it holds more mass than our Sun.
26The astronomers call this kind of star a "black widow."
27The name comes from a kind of spider.
28The black widow female is known to eat the male after mating.
29Astronomers call star systems with related qualities "spider binaries."
30The star is believed to have started as a neutron star with the usual mass, about 1.4 times that of our sun.
31But its gravitational pull took material from the star in its system.
32That appears to have caused it to gain mass nearing the physical limit.
33eyond that limit, scientists say, the star should collapse into a black hole.
34Black holes are the densest of all known objects.
35The other star in the system has lost about 98 percent of its mass to the black widow star.
36It remains about 20 times the mass of our solar system's largest planet, Jupiter.
37But far less massive than a normal star.
38I'm Gregory Stachel.
1Space scientists have observed what they believe is the most massive known example of an object called a neutron star. 2It has been called a "black widow" since it gained much of its mass by taking it from another star which it orbits. 3The star recently discovered by astronomers turns more than seven hundred times every second. Its mass is 2.35 times greater than our sun. The researchers said the star is close to the highest possible mass for an object of its kind. If it were any more massive it would collapse into a massive black hole. 4The researchers published their findings recently in Astrophysical Journal Letters. 5A neutron star is the dense, collapsed center, or core, of a massive star that exploded in an event called a supernova. This neutron star is a kind that is highly magnetized, called a pulsar. From Earth, pulsars appear to give off light repeatedly in short moments, like a lighthouse. 6Only one other neutron star is known to turn more quickly. 7Roger Romani is director of Stanford University's Center for Space Science and Astrophysics in the U.S. state of California. He helped write the research. Romani said, "The heavier the neutron star, the denser the material in its core." 8Romani added, "So as the heaviest neutron star known, this object presents the densest material in the observable universe. If it was any heavier it should collapse to a black hole, and then the stuff inside would be behind the event horizon, forever sealed off from any observation." 9Scientists use the term "event horizon" to describe a point close to a black hole beyond which nothing can escape including light. 10Romani said, "Since we don't yet know how matter works at these densities, the existence of this neutron star is an important probe of these physical extremes." 11The star is officially known as PSR J0952-0607. It is about 20,000 light years from Earth. A light year is the distance light travels in a year. The researchers studied it using the Keck I telescope in the state of Hawaii. 12Stars that are about eight or more times the sun's mass change the chemical hydrogen into heavier elements. When they build up about 1.4 times the mass of our sun in the element iron, their core collapses into a neutron star. 13A neutron star is very small-about the size of a city. But within that small area, it holds more mass than our Sun. 14The astronomers call this kind of star a "black widow." The name comes from a kind of spider. The black widow female is known to eat the male after mating. Astronomers call star systems with related qualities "spider binaries." 15The star is believed to have started as a neutron star with the usual mass, about 1.4 times that of our sun. But its gravitational pull took material from the star in its system. 16That appears to have caused it to gain mass nearing the physical limit. Beyond that limit, scientists say, the star should collapse into a black hole. Black holes are the densest of all known objects. 17The other star in the system has lost about 98 percent of its mass to the black widow star. It remains about 20 times the mass of our solar system's largest planet, Jupiter. But far less massive than a normal star. 18I'm Gregory Stachel. 19Will Dunham reported this story for Reuters. Gregory Stachel adapted it for VOA Learning English. 20________________________________________________________________________ 21Words in This Story 22astronomer -n. a scientist who studies stars, planets, and other objects in outer space 23seal - v. to close (something) tightly so that air or liquid cannot get in or out 24probe - n. careful examination or investigation of something 25_______________________________________________________________________ 26What do you think of astronomy? 27We want to hear from you. We have a new comment system. Here is how it works: 28Each time you return to comment on the Learning English site, you can use your account and see your comments and replies to them. Our comment policy is here.