### star:

Neutron star
* Most neutron stars are detected as pulsars
  - hard to study as they are a billion or more light-years away
  - created by supernovas are pulsars
* Some neutron stars appear to emit regular pulses of electromagnetic radiation
  - rotate rapidly and give off regular, intense bursts of radio waves
* are a unique laboratory for probing various physical phenomena
  - all that is left after a star has exploded in a supernova
  - almost as strange as dark matter
  - also pretty rare
* are among the most exotic astronomical objects known
  - fascinating astronomical objects in the universe
  - an entity of theoretical astrophysics
  - detected from their electromagnetic radiation
  - extreme in many other ways, too
  - extremely stable rotators
* are fascinating objects that are involved in many high energy phenomena
  - objects, because they are the most dense objects known
  - formed when large stars run out of fuel and collapse
  - incredibly dense - similar to the density of an atomic nucleus
  - like no other object
  - likewise the endpoints of more massive stars, which are less numerous
* are one of the possible end-products of stellar evolution
  - ends for a star
  - potentially powerful energy sources
* are really dense
  - just enormous nuclei
  - small and can spin rapidly without being torn apart
* are the collapsed cores of some massive stars
  - remnants of stellar cores
  - dense cinders left behind when massive stars explode in supernovae
  - fastest spinning stars known
  - incredibly dense remnants of ancient stars
  - size of mountains and weigh as much as a star
  - smallest and densest stars known to exist
  - thus what is left over after the star has died
  - typically a few kilometers in diameter
* are very dense , and have short , regular spins
  - short, regular rotational periods
  - dense, only ten or twenty kilometres across, but more massive than our Sun
* are very small and dense
  - by astronomical standards
  - strange places
* can rotate hundreds of times per second
  - theoretically collapse into black holes if they accrete enough matter
* come from the death of big stars.
* comprise one of the possible evolutionary end-points of high mass stars.
* have a solid crust, and a superfluid core
  - strong gravitational field and some emit pulses of energy along their axis
  - an interesting property, which involves their rotation rate
  - diameters of a few tens of kilometres, depending on their mass
  - powerful magnetic fields
  - strong magnetic fields
  - very strong magnetic fields
* release energy by spewing light, radio waves and particles.
* resist gravitational collapse via neutron degeneracy pressure.
* rotate much faster than other stars.
* send out rapidly-varying radio emissions, and are therefore called pulsars
  - strong beams of x-rays, and spin very fast
* tend to have rapid rotation and very strong magnetic fields.
* wander far from their places of birth before merging, whereas hypernovae stay put.
+ Neutron star, Properties, Density
  * Neutron stars are very dense. They are much denser than anything we find naturally on the Earth
  * Neutron stars have very strong magnetic fields. They are some of the strongest magnetic fields that occur naturally
  - Rotation: Types of stars :: Astrophysics
+ Pulsar: Variable stars :: Astrophysics
  * Pulsars' are neutron stars which spin rapidly and produce huge electromagnetic radiation along a narrow beam. Neutron stars are very dense, and have short, regular spins. This produces a very precise interval between pulses that range from roughly milliseconds to seconds for an individual 'pulsar'. The pulse can only be seen if the Earth is close enough to the direction of the beam.