WASHINGTON: Astronomers have discovered the most massive neutron star known to science. Dubbed a “black widow,” it gained its size by consuming the majority of the mass of a stellar companion caught in an unhappy cosmic union.
According to the researchers, the neutron star is wildly spinning at 707 times per second and has a mass that is about 2.35 times greater than our sun, which may be the maximum mass that such objects can have before collapsing into a black hole.
A massive star’s compact collapsed core, which resulted from a supernova explosion at the end of its life cycle, is what makes up a neutron star. The neutron star that the researchers describe is a pulsar, a type of highly magnetized neutron star that emits electromagnetic radiation beams from its poles. From the viewpoint of an observer on Earth, these beams appear to pulse as it spins, similar to the rotating light of a lighthouse.
It is known that only one other neutron star spins more quickly than this one.
According to Roger Romani, director of Stanford University’s Center for Space Science and Astrophysics and a co-author of the study that was published this week in the Astrophysical Journal Letters, “the heavier the neutron star, the denser the material in its core.”
Given that it is the heaviest neutron star known, Romani continued, “this object presents the densest material in the observable universe; if it were any heavier it should collapse to a black hole, and at that point the matter inside would be behind the event horizon, forever sealed off from any observation.”
The event horizon of a black hole is the boundary beyond which all matter, including light, is irretrievably sucked in.
The existence of this neutron star, according to Romani, “is an important probe of these physical extremes since we do not yet know how matter works at these densities.”
According to Romani, the neutron star, officially known as PSR J0952-0607, is situated in our Milky Way galaxy in the direction of the constellation Sextans and is about 20,000 light years away from Earth. 5.9 trillion miles is the distance that light travels in a year, or a light year (9.5 trillion km). The Keck I telescope in Hawaii was used by the researchers to study it.
Thermonuclear fusion occurs in the cores of stars with masses of about eight or more times that of the sun, converting hydrogen into heavier elements. The iron core collapses into a neutron star with a diameter of only about a city when it builds up to about 1.4 times the mass of our sun, with the remaining material being blown away in the supernova explosion.
This neutron star shares an orbit with another star in a configuration known as a binary system. The term “black widow” was given to the type of neutron star in honor of female black widow spiders that consume their male mates after mating.
Apparently, it was born with a neutron star’s typical mass, which is roughly 1.4 times that of the sun, but its gravitational pull has changed over time.
Its companion star has been nearly stripped bare by the black widow, losing perhaps 98 percent of its mass, leaving it at 20 times the mass of Jupiter, the largest planet in our solar system, a far cry from its original size.
According to study co-author and University of California, Berkeley astronomy professor Alex Filippenko, “in a case of cosmic ingratitude, the black widow pulsar, which has devoured a large portion of its mate, now heats and evaporates the companion down to planetary masses and possibly complete annihilation.”
