The most massive neutron star ever detected was found. Named J0740+6620, it is 2.17 times the mass of the sun, which is 333,000 times the mass of the Earth.
This is close to the limit of how much mass a compact object can contain before it crushes itself into a black hole. A sugar-cube's worth of neutron-star material has a mass of about 100 million tons, or about the same as the entire human population. The star was detected by the Green Bank Telescope in West Virginia when they searched for gravitational waves. Neutron stars form when the outer part of a giant sun explodes and the core implodes. Its protons and electrons melt into each other to form neutrons. This one was detected about 4,600 light years from Earth by the Green Bank Telescope in West Virginia.
As a common fact, neutron stars have temperatures of a million degrees, are highly radioactive and have intense magnetic fields. Neutron stars are the smallest in the universe, with a diameter comparable to the size of a city like Chicago or Atlanta. "Neutron stars are as mysterious as they are fascinating," said Thankful Cromartie, a graduate student at the University of Virginia and Grote Reber pre-doctoral fellow at the National Radio Astronomy Observatory in Charlottesville, Virginia.