Neutron Stars
Ultra-dense remnants from core-collapse supernovae.
Overview
Neutron stars are city-sized stellar remnants (~20 km diameter) with masses up to ~2 M☉, supported by neutron degeneracy pressure.
Why It Matters
Neutron stars are cosmic laboratories for extreme physics — densities exceeding atomic nuclei, magnetic fields trillions of times Earth's.
Scientific Explanation
Core-collapse supernovae crush stellar cores past white dwarf limit (Chandrasekhar 1.4 M☉). Protons and electrons merge to neutrons. A teaspoon weighs billions of tons. Magnetars have fields strong enough to distort atoms. Glitches reveal superfluid interiors.
Historical Background
Chandrasekhar predicted mass limit (1930). Oppenheimer calculated neutron star structure (1939). Bell Burnell discovered pulsars (1967). LIGO detected neutron star merger GW170817 (2017).
Visual Explanation
Imagine compressing the Sun to the size of Manhattan. Rotation speeds up (conservation of angular momentum) — pulsars spin hundreds of times per second.
Key Discoveries
- ✦ First pulsar CP 1919 discovered
- ✦ Vela glitch proves superfluid core
- ✦ GW170817: neutron stars + gravitational waves + kilonova
- ✦ NICER maps neutron star sizes
Important Astronomers
Reflection Prompt
Matter can exist in states stranger than fiction. What limits does nature place on density?
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