# Gravity Defied (from potato asteroids to magnetised neutron stars) IV. Neutron Stars (dead stars of the second kind)

## TL;DR

This paper explores the physics of neutron stars, dense remnants of massive stars, focusing on their formation, structure, and the unique states of matter under extreme densities.

## Contribution

It provides a detailed analysis of neutron star formation and the physical phenomena arising from their ultra-dense matter, expanding understanding of stellar evolution endpoints.

## Key findings

- Neutron stars contain matter at nuclear densities.
- They exhibit unique physical phenomena due to extreme compactness.
- Neutron star physics informs understanding of matter under extreme conditions.

## Abstract

A star burns its nuclear fuel and balances gravitation by the pressure of the heated gas, during its active lifetime. After the exhaustion of the nuclear fuel, a low mass star finds peace as a {\em white dwarf}, where the pressure support against gravitation is provided by Fermi-degenerate electrons. However, for massive stars the gravitational squeeze becomes so severe that in the final phase of evolution, the average density approximately equals the nuclear density. At such densities most of the protons combine with electrons to convert themselves into neutrons. A {\em Neutron star}, composed of such neutron-rich material, is host to some fascinating physics arising out of its amazingly compact state of matter (where a solar mass is packed inside a sphere of radius $\sim$ 10Km).