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 2.14+0.10
−0.09 solar masses[1] placing it near the boundary of the theoretical maximum.[2] 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 10 kilometres (6.21 mi) in size, PSR J0740+6620 is estimated at 30 km (18.64 mi) across.[citation needed]
References
- ^ Cromartie, H. T.; Fonseca, E.; Ransom, S. M.; et al. (2019). "Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar". Nature Astronomy. arXiv:1904.06759. doi:10.1038/s41550-019-0880-2.
- ^ Green Bank Observatory (September 16, 2019). "Most massive neutron star ever detected, almost too massive to exist". ScienceDaily. Retrieved September 26, 2019.
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