Oppenheimer limit is stableneutron starThe upper quality limit of.In 1936, Oppenheimer and others proved that there was aCritical mass, onethermonuclearIf the mass of an energy exhausted star is greater than this critical mass, it cannot be stableneutron starIt either collapses infinitely to form a black hole, or forms other types ofCompact starThis critical mass is called Oppenheimer limit.
In 1936, Oppenheimer and others first discussedneutron stateCorporealCompact starThe equilibrium and stability of neutron stars.The properties of such stars are mainly determined by the balance between self gravity and degenerate neutron pressure.No rotation using general relativitySpherically symmetricAstral bodystructural equation And the ideal Fermi gas equation is used as theEquation of stateOppenheimer and others proved that there is aCritical massM ≈ 0.75M, M meansSolar mass。When the mass of the star is less than M, there is a stable equilibrium solution;On the contrary, there is no stable equilibrium solution.The upper limit M of the mass of a neutron star is the Oppenheimer limit.If the equation of state of neutron which is closer to the reality is adopted.The value of Oppenheimer limit will be different from the original value.Since the equation of state for density greater than 10 g/cm is still uncertain, and the upper limit of mass of neutron star is also uncertain, it can be generally taken as 2M.
Oppenheimer limit (TOV limit, also known as Oppenheimer Volkow limit) is the upper limit of the mass of neutron stars, similar toWhite dwarfUpper quality limitChandraseka limit。As mentioned in the above section, the upper limit of neutron star mass obtained by Oppenheimer and Volkow is about 0.7 times the solar mass, which should be wrong today. Today's result is between 1.5 and 3 times the solar mass.For a neutron star whose mass is less than this limit, the internal pressure of the supporting star comes from theStrong interactionAnd the quantum of neutron itselfDegeneracy pressure；For a neutron star whose mass is greater than this limit, it will collapse under its own gravity, thus collapsing into a black hole. Theoretically, it is in the interior of other waysPressure supportIt may also become other forms of stars (such asquarkCollapse toQuark star）。However, due to less understanding of these theoretical quark degenerate matter than neutron degenerate matter, ordinary celestial bodiesphysical scientistBelieve that unless there is actual observationCounterexampleIt is confirmed that neutron stars will directly collapse into black holes when they exceed this limit.
OnethermonuclearIf the mass of an energy exhausted star is greater than the Oppenheimer limit, it cannot become a stable neutron star.One possible destination is to form a black hole through infinite collapse, and the other is to form other types between neutron stars and black holesCompact star。
Oppenheimer was responsible for organizing the Los Alamos Laboratory belonging to the Manhattan Project in 1942, and served as the director of the laboratory the following year.During this period, he organized and led a large number of world-famous physicists to research and design the first atomic bombs.It is called "the father of the atomic bomb".the Second World WarLater, he opposed making in the United StatesHydrogen bomb, claimatomic energyPeaceful utilization;Has beenmccarthyismPersecution of people (namely the so-calledOppenheimer case）。
