Neutron star

Assembled from 36 blocks · 3 evidence · 32 related

1. Story
2. What remains when a massive star's core collapses and stops. Roughly one and a half solar masses are compressed into a sphere on the order of twelve kilometres across, at densities comparable to an atomic nucleus, supported by neutron degeneracy together with the repulsive core of the strong interaction. The upper mass bound is not known precisely because it depends on the equation of state of matter at densities no laboratory can reach; the heaviest reliably measured neutron star, the pulsar PSR J0740+6620, has a gravitational mass of 2.08 plus or minus 0.07 solar masses, and independent analyses of the same NICER and XMM-Newton data gave equatorial radii near 12.4 km and near 13.7 km - a real disagreement at the level that matters for the physics. Neutron stars were hypothesised in 1934, two years after the neutron was discovered, and observed only in 1967. Not a place on Earth.
3. Knowledge
4. Degeneracy pressure
5. Supernova
6. Neutron star
7. Connections
8. Degeneracy pressure
9. Supernova
10. Baade and Zwicky propose supernovae and neutron stars
11. A regularly pulsing radio source is identified
12. A pulsar is found inside the Crab Nebula
13. SN 1987A: neutrinos from a collapsing core reach Earth
14. A neutron-star merger is detected in gravitational waves and light
15. A radius is measured for the heaviest known neutron star
16. JWST finds the compact object in SN 1987A
17. Chandrasekhar limit
18. White dwarf
19. Neutron star
20. A maximum mass for ideal white dwarfs is published
21. A radius is measured for the heaviest known neutron star
22. Initial stellar mass
23. The iron peak in nuclear binding energy
24. Giant molecular cloud
25. Neutron star
26. Stellar-mass black hole
27. A guest star appears in Taurus and is recorded in East Asia
28. Baade and Zwicky propose supernovae and neutron stars
29. A pulsar is found inside the Crab Nebula
30. SN 1987A: neutrinos from a collapsing core reach Earth
31. SN 1987A: neutrinos from a collapsing core reach Earth
32. JWST finds the compact object in SN 1987A
33. Evidence
34. 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.
35. Reports the first pulsar, CP 1919, with a period near 1.337 s. Journal, volume and page come from institutional summaries of the discovery read via search; the paper was not fetched, and the 28 November 1967 identification date and the exact period value are from University of Cambridge and American Physical Society accounts rather than the paper.
36. Introduces the term super-nova, proposes the transition of an ordinary star into a star of closely packed neutrons, and links such events to cosmic rays. Volume and page numbers are deliberately not asserted because they were not confirmed; the content is known through a later PNAS retrospective read via search summary.