Astronomers have found the largest example yet of the dead stars often called neutron stars, one virtually too massive to exist, new research finds.
Neutron stars are corpses of stars that died in catastrophic explosions called supernovas. When a star goes supernova, the crucial part of its remains collapses under the power of its own gravitational force. If this remnant is massive enough, it might form a black hole, which has powerful gravity that does not even let light to escape.
Neutron stars are often small, with diameters of about 12 miles (19 kilometers) or so; however, they’re extremely dense. A neutron star’s mass is usually about the same as that of the sun; a sugar cube’s worth of neutron-star material has a mass of about 100 million tons, or about the same as the whole human population, based on the statement. This makes neutron stars the universe’s most solid objects besides black holes.
The newly mapped neutron star, named J0740+6620, lies about 4,600 light-years from Earth. It packs 2.14 times the weight of the sun into a sphere only about 15 miles (25 km) in diameter. That approaches the theoretical limits of how huge and compact a single object can become without crushing itself down under the pressure of its own gravitational pull into a black hole.
J0740+6620 is a rotating neutron star often called a pulsar. Pulsars emit dual beams of radio waves from their magnetic poles, flashing like lighthouse guides.