An international team of astronomers has discovered an unknown object in the Milky Way that is more massive than the heaviest known neutron stars, but at the same time lighter than the lightest black holes. This discovery, made using the MeerKAT radio telescope, was published in the journal Science.
The object, located about 40,000 light-years away in the densely populated star cluster NGC 1851, orbits a rapidly rotating millisecond pulsar. The discovery could be the first time a radio pulsar-black hole system has been detected, opening up new opportunities for testing Einstein’s general theory of relativity and studying black holes.
Ben Stappers, professor of astrophysics at the University of Manchester and project leader in the UK, stressed that any nature of the satellite is an exciting discovery. The pulsar-black hole system will be an important target for testing theories of gravity, and the heavy neutron star will provide new opportunities for studying nuclear physics at very high densities.
Astronomers believe that a neutron star would need to have 2.2 times the mass of the Sun to collapse. The lightest black holes formed by these stars are thought to be five times more massive than the Sun, creating the so-called “black hole mass gap.” The nature of the compact object in this gap was previously unknown. The discovery was made during observations of the large star cluster NGC 1851 in the constellation Pigeon. Because the stars in this globular cluster are so densely packed, they can interact with each other, disrupt their orbits, and in extreme cases even collide. Scientists believe that the collision of two neutron stars may lead to the formation of this giant object. Using a technique called “pulsar timing,” scientists were able to measure the orbital motion of pulsars with high precision. Evan Bahr of the Radio Astronomy Research Institute. Lead researcher Max Planck compared this to being able to measure the orbit of a star nearly 40,000 light-years away with microsecond precision using a near-perfect clock. Arunima Dutta, co-author of the research paper, says that by revealing the true nature of satellites, we will understand more about neutron stars, black holes, and other astronomical objects that may be hiding in black hole mass gaps. It is emphasized that this will change fundamentally.