PSR J0740+6620
PSR J0740+6620 is a neutron star in a binary system with a white dwarf, located 4,600 light years away. It was discovered in 2019, by astronomers using the Green Bank Telescope in West Virginia, U.S., and confirmed as a rapidly rotating millisecond pulsar.
As of 2019, it is among the most massive neutron stars ever observed – with solar masses placing it near the boundary of the theoretical maximum. Its mass was calculated via the Shapiro delay of its white dwarf companion as it passed edge-on to Earth.
While most neutron stars are typically around in size, PSR J0740+6620 is estimated at across.
