Researchers have spotted a “black widow” lurking in space 3,000 light-years from Earth, and it’s a record-breaking cosmic object.
Called a neutron star, the dense, collapsed remnants of a massive star weigh more than twice the mass of our Sun, making it the heaviest neutron star known to date.
The object rotates 707 times per second, which also makes it one of the fastest rotating neutron stars in the Milky Way.
The neutron star is known as the black widow because, just as female spiders consume much smaller male mates after mating, the star has destroyed and devoured nearly all of its mate’s mass.”
This stellar feast allowed the black widow to become the heaviest neutron star observed so far. The Astrophysical Journal Letters published a study detailing the findings on Monday (25).
Astronomers were able to weigh the star, named PSR J0952-0607, using the sensitive Keck telescope at the WM Keck Observatory in Maunakea, Hawaii.
The observatory’s low-resolution imaging spectrometer recorded visible light from the fragmented companion star, which glowed due to its high heat.
The companion star is now the size of a large gas planet, or 20 times the mass of Jupiter. The side of the companion star facing the neutron star is heated to 5,927°C — hot and bright enough to be seen by a telescope.
Neutron star cores are the densest matter in the universe outside of black holes, and 1 cubic inch (16.4 cubic centimeters) of a neutron star weighs more than 10 billion tons, according to the study’s author. Roger W. Romani, professor of physics at Stanford University in California.
This particular neutron star is the densest object within sight of Earth, according to the researchers.
“We know roughly how matter behaves at nuclear densities, such as in the nucleus of a uranium atom,” study co-author Alex Filippenko said in a statement. Filippenko holds two titles of professor of astronomy and distinguished professor of physical sciences at the University of California, Berkeley.
“A neutron star is like a giant core, but when you have one and a half solar masses of this material, which is about 500,000 Earth masses of cores all stuck together, it’s not clear how they will behave.”
A neutron star like PSR J0952-0607 is called a pulsar because as it spins, the object acts like a cosmic beacon, regularly emitting light through radio waves, X-rays, or gamma rays.
Normal pulsars spin and flash about once a second, but this one is pulsating hundreds of times a second. This is because the neutron star becomes more energized as it pulls material from the companion star.
“In a case of cosmic ingratitude, the black widow pulsar, which devoured much of its companion, now heats up and evaporates the companion to planetary masses and perhaps complete annihilation,” Filippenko said.
Astronomers first discovered the neutron star in 2017, and Filippenko and Romani have studied similar black widow systems for more than a decade. They have been trying to understand how large neutron stars can become. If neutron stars become too heavy, they will collapse and become black holes.
The star PSR J0952-0607 is 2.35 times the mass of the Sun, which is now considered the upper limit for a neutron star, the researchers said.
“We can keep looking for black widows and similar neutron stars that come even closer to the edge of the black hole. But if we don’t find any, it reinforces the argument that 2.3 solar masses is the true limit, beyond which they become black holes,” Filippenko said.
Source: CNN Brasil
