PSR J0952−0607

Summary

PSR J0952−0607 is a massive millisecond pulsar in a binary system, located between 3,200–5,700 light-years (970–1,740 pc) from Earth in the constellation Sextans. As of 2022, it holds the record for being the most massive neutron star known, with a mass 2.35±0.17 times that of the Sun—potentially close to the Tolman–Oppenheimer–Volkoff mass upper limit for neutron stars. The pulsar rotates at a frequency of 707.31 Hz, making it the second-fastest-spinning pulsar known, and the fastest-spinning pulsar known within the Milky Way.