Black hole or neutron star?
(NewsNation) – A team of astronomers has discovered a new, unknown object in the Milky Way that could shed light on the formation of black holes.
The object may be a real black hole, or it may not be. Its mass is heavier than the heaviest known neutron star, and at the same time lighter than the lightest known black hole.
Whatever the object is, it lives in what is known as a “black hole’s mass gap,” the researchers wrote in the study published Thursday in the journal Science. It was found to orbit a radio pulsar, a type of neutron star that spins rapidly and emits beams of radio light.
“Any possibility of the nature of (the object) is exciting,” Ben Stubbers, a professor of astrophysics at the University of Manchester, said in a press release. “The pulsating black hole system will be an important target for testing theories of gravity, and the heavy neutron star will provide new insights into nuclear physics at very high densities.”
The researchers concluded that the object was formed as a result of the merger of two other neutron stars, which are the collapsed cores of giant stars.
Neutron stars themselves can collapse, and when that happens, it’s thought they can become black holes, objects with such a strong gravitational pull that not even light can escape. Most observed black holes have a mass of about five times the mass of the Sun, but they can be as light as 2.2 times the mass of the Sun.
The newly identified object, discovered by the MeerKAT radio telescope, has a mass between 2.09 and 2.71 solar masses. The nature of the objects inside the so-called “mass gap” is unknown, and this discovery may help astronomers learn more about such objects.
“The ability of the highly sensitive MeerKAT telescope to detect and study these objects is a major step forward,” Stubbers said.
Astronomers found the object while looking at a cluster of stars known as NGC 1851, an incredibly dense collection of ancient stars. They detected rays of light coming from a radio pulsar, which rotates more than 170 times per second and produces a rhythmic pulse like the ticking of a clock.
The mass of both objects was calculated by measuring those ticks.
“Observations showed… that (the object) has a mass greater than that of any known neutron star and yet smaller than the mass of any known black hole, placing it directly in the black hole’s mass gap,” the press release said. .
While astronomers have not been able to conclusively classify the object as either a neutron star or a black hole, its discovery should open the door to studying the properties of very dense objects in the universe.
“We’re not done with this system yet,” said Arunima Dutta, one of the study’s co-authors. “Revealing the true nature of this (object) will be a turning point in our understanding of neutron stars, black holes, and anything else that might lurk in the black hole’s mass gap.”