Astrophysics (index)about

neutron star

(stellar remnant consisting entirely of solar masses of neutrons)

A neutron star is a mass entirely of neutrons the result of gravitational collapse of a star after it has used up the energy to resist such collapse. Its mass is large enough that gravity overcomes electron degeneracy and causes such collapse but not so large as to overcome their internal pressure which prevents them collapsing into a black hole (neutron degeneracy pressure). Typical mass is 1.4 to 3.2 solar masses with a radius on the order of 10 km. Stars with lesser mass become white dwarves instead.

Their existence was first proposed in 1934 and candidates were identified in the 1960s that have panned out.

Rotation of neutron stars and their magnetic field makes them pulse (pulsars). The magnetic field may be strong enough to affect the trajectory of accretion, channeling it to the magnetic poles. The point where the magnetic field is sufficiently strong to overcome the accreting mass's kinetic energy is called the Alfvén radius.

They are more complex than a mere "mass of neutrons" as the pressures at different depths produce different states of matter at different densities. They are thought to include iron at the surface, with something more like a simple mass of neutrons deeper, at which depths the material gains superfluid (no friction) and superconducting fluid (no electrical resistance) characteristics.

(star type,degeneracy,stellar evolution)

Referenced by:
Black Widow Pulsar (B1957+20)
black hole binary (BHB)
binary star
binary neutron star (BNS)
Bondi radius
calcium-rich gap transient
Chandrasekhar limit
Canadian Institute for Theoretical Astrophysics (CITA)
compact object
electron degeneracy
fast radio burst (FRB)
globular cluster (GC)
gravitational redshift
gamma-ray burst (GRB)
gravitational wave (GW)
GW detection (GW)
gravitational wave spectrum
hypermassive neutron star (HMNS)
innermost stable circular orbit (ISCO)
isothermal core
Crab Nebula (M1)
neutron drip
neutron star merger
pion (π)
post main sequence star
Hulse-Taylor Binary (PSR B1913+16)
pulsar (PSR)
radio star
rotation period
supernova remnant (SNR)
SS 433
stellar evolution
stellar remnant
stellar rotation
strong-field gravity
tidal tail
Tolman-Oppenheimer-Volkoff limit (TOV)
Thorne-Żytkow object (TZO)
Urca process
white dwarf
X-ray source (RS)