Astronomers using NSF’s Green Bank Telescope have identified a record breaking neutron star with the highest mass yet known. The object, called MSP J0740+6620, is a rapidly rotating millisecond pulsar that packs 2.14 solar masses into a sphere only 15 miles (24 km) across. This measurement approaches the limits of how massive and compact a single object can become without crushing itself down into a black hole. MSP J0740+6620. Image credit: B. Saxton...