Relativistic star
Encyclopedia
A relativistic star is a rotating neutron star
whose behavior is well described by general relativity
, but not by classical mechanics
. Relativistic stars are one possible source to allow gravitational wave
s to be studied.
Another definition of a relativistic star is one with the equation of state
of a special relativistic
gas. This can happen when the core of a massive main sequence
star becomes hot enough to generate electron
-positron
pairs
. Stability analysis shows that such a star is only marginally bound, and is unstable to either collapse or explode. This instability is believed to limit the mass of main sequence stars to a couple of hundred solar masses or so. Stars of this size and larger are able to directly collapse into a black hole of either intermediate or supermassive
size.
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
whose behavior is well described by general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
, but not by classical mechanics
Classical mechanics
In physics, classical mechanics is one of the two major sub-fields of mechanics, which is concerned with the set of physical laws describing the motion of bodies under the action of a system of forces...
. Relativistic stars are one possible source to allow gravitational wave
Gravitational wave
In physics, gravitational waves are theoretical ripples in the curvature of spacetime which propagates as a wave, traveling outward from the source. Predicted to exist by Albert Einstein in 1916 on the basis of his theory of general relativity, gravitational waves theoretically transport energy as...
s to be studied.
Another definition of a relativistic star is one with the equation of state
Equation of state
In physics and thermodynamics, an equation of state is a relation between state variables. More specifically, an equation of state is a thermodynamic equation describing the state of matter under a given set of physical conditions...
of a special relativistic
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
gas. This can happen when the core of a massive main sequence
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
star becomes hot enough to generate electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
-positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
pairs
Pair production
Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon . For example an electron and its antiparticle, the positron, may be created...
. Stability analysis shows that such a star is only marginally bound, and is unstable to either collapse or explode. This instability is believed to limit the mass of main sequence stars to a couple of hundred solar masses or so. Stars of this size and larger are able to directly collapse into a black hole of either intermediate or supermassive
Supermassive black hole
A supermassive black hole is the largest type of black hole in a galaxy, in the order of hundreds of thousands to billions of solar masses. Most, and possibly all galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.Supermassive black holes have...
size.