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neutron star
subject			fact

neutron star	has definition A dead, collapsed star that consists mostly of neutrons and is only about 20 kilometers across. Neutron stars are much denser than white dwarfs.
	has definition A star whose core is composed primarily of neutrons, as is expected to occur when the mean density is in the range 1013-1015 g cm-3. Under current theories pulsars are assumed to be rotating magnetic neutron stars. A neutron star would probably be only 10-15 km in diameter with a magnetic field of about 1012 gauss, a density of 1013-1015 g cm-3 (compared with a white dwarf's maximum density of about 108 g cm-3) and a central temperature of about 109 K and thus would be both bluer and dimmer than a white dwarf.
	has definition Remnant of a star after it has exploded as a supernova. Usually optically dim, a neutron star sends out regular or irregular radio emissions and is therefore also called a pulsar. The density of such a star may be unimaginably great although the diameter is generally around only 10 km; the gravitational and magnetic forces are correspondingly vast. It is called a neutron star because in such density, protons fuse with electrons to form neutrons, of which the star is almost entirely composed.
	is a kind of star
	is a kind of massive compact halo object
massive compact halo object	is a part of halo
	has acronym MACHO
star	has star surface temperature
	has spectral type
	has V magnitude
	has B magnitude
	has U magnitude
	has position on celestial sphere from the point of view of Earth
	has parallax from the point of view of Earth's orbit
	has proper motion
	has radiation at surface which is diffused out from the hotter core
	has energy source gravitational contraction and or fusion
	has energy production which takes place primarily within the core
	has surface density which depends on luminosity class
	has surface temperature greater than 1000 Kelvin
	has apparent magnitude
	has absolute magnitude
	has age
	has catalog star catalog
	has material hydrogen, helium
	has velocity determined from proper motion and radial velocity
	has mass greater than 0.08 the sun's mass
dark matter	is a part of dark halo
	has synonym hidden mass
celestial body	has spectra
hypothetical particle	has acceptance status hypothetical
particle	obeys uncertainty principle
	has frequency inversely proportional to the wavelength
	has wavelength inversely proportional to its momentum
	has charge
physical object	has location or center of gravity
	has angular momentum
	has momentum
	has temperature
	has volume
	has extent

Kinds of neutron star :

• pulsar (8 kinds, 50 facts) (PSR) - A fast-spinning neutron star that emits radiation toward Earth every-time it rotates., Neutron stars that spin rapidly and have strong magnetic fields, which produce electromagnetic radiation. (See neutron star.), An object discovered at Cambridge University in 1967 which has the mass of a star and a radius no larger than that of Earth and which emits radio pulses with a very high degree of regularity (periods range from 0.03 s for the youngest to more than 3 s for the oldest). All pulsars are characterized by the general properties of dispersion, periodicity, and short duty cycle. Pulsars are believed to be rotating, magnetic (surface magnetic fields of 10¹⁰ to 10¹⁴ gauss are estimated) neutron stars which are the end products of supernovae. Type S pulsars have a simple pulse shape: Type C, complex: Type D have drifting subpulses.
• ROSAT PRC97-32 (5 facts)

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