A radius is measured for the heaviest known neutron star
X-ray timing of hot spots on the rotating surface of PSR J0740+6620, using NICER together with XMM-Newton data, produced the first radius measurement for a neutron star of about 2.08 solar masses. Two independent analyses of largely the same data reported equatorial radii near 12.4 km and near 13.7 km, a spread that matters because the mass-radius relation is the observational handle on the equation of state of matter at densities beyond nuclear saturation.
Observed — measured or witnessed, with the observation cited.
Subjects
- Neutron star · celestial body · Galactic · not located
- Degeneracy pressure · concept · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
The Radius of PSR J0740+6620 from NICER and XMM-Newton Data
Provides a mass of 2.08 +/- 0.07 solar masses and radius estimates for the heaviest reliably measured neutron star. Journal, volume, page and DOI come from ADS and publisher listings via search; neither paper was fetched. The two radius values quoted in this pack (near 12.4 km and near 13.7 km) come from independent analyses reported in a search summary and are given as a disagreement rather than reconciled.
The Astrophysical Journal Letters · 2021 · Partly verified
M. C. Miller et al., ApJL 918, L28 (2021); DOI 10.3847/2041-8213/ac089b. A later reanalysis with updated NICER data appeared as "A More Precise Measurement of the Radius of PSR J0740+6620 Using Updated NICER Data", ApJ (2024)
Recorded on Neutron star
- A maximum mass for ideal white dwarfs is published
- Baade and Zwicky propose supernovae and neutron stars
- A regularly pulsing radio source is identified
- A pulsar is found inside the Crab Nebula
- SN 1987A: neutrinos from a collapsing core reach Earth
- A neutron-star merger is detected in gravitational waves and light
- A radius is measured for the heaviest known neutron star
- JWST finds the compact object in SN 1987A
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- JWST finds the compact object in SN 1987A · 2024-02-22
- A neutron-star merger is detected in gravitational waves and light · 2017-08-17
- SN 1987A: neutrinos from a collapsing core reach Earth · 1987-02-23 ~07:35 UT (neutrinos); optical discovery 1987-02-24
- A pulsar is found inside the Crab Nebula · 1968
- A regularly pulsing radio source is identified · 1967-11-28
- Baade and Zwicky propose supernovae and neutron stars · 1934
- A maximum mass for ideal white dwarfs is published · 1931