Innermost Stable Circular Orbit

The Innermost Stable Circular Orbit (often called the ISCO) is the smallest orbit in which a test particle can stably orbit a massive object in general relativity.^[1] The location of the ISCO, the ISCO-radius (), depends on the angular momentum (spin) of the central object. For a non-spinning object, a where the gravitational field can be expressed with the Schwarzschild metric, the ISCO is located at,

As the angular momentum of the central object increases, decreases. Even for a non-spinning object, the ISCO radius is only three times the Schwarzschild Radius, suggesting that only black holes have innermost stable circular orbits outside of their surfaces.

References

• Misner, Charles; Thorne, Kip S.; Wheeler, John (1973). Gravitation. W. H. Freeman and Company. ISBN 0-7167-0344-0. 

External links

Relativity Special relativity Background Principle of relativity Introduction to special relativity Special relativity Foundations Relative motion Frame of reference Speed of light Maxwell's equations Formulation Galilean relativity Galilean transformation Lorentz transformation Consequences Time dilation Relativistic mass Mass–energy equivalence Length contraction Relativity of simultaneity Relativistic Doppler effect Thomas precession Relativistic disks Spacetime Minkowski spacetime World line Spacetime diagrams Light cone General relativity Background Introduction Mathematical formulation Resources Fundamental concepts Special relativity Equivalence principle World line Riemannian geometry Minkowski diagram Phenomena Two-body problem Lenses Waves Frame-dragging Geodetic effect Event horizon Singularity Black hole Equations Linearized gravity Post-Newtonian formalism Einstein field equations Geodesic equation Friedmann equations ADM formalism BSSN formalism Hamilton–Jacobi–Einstein equation Advanced theories Kaluza–Klein Quantum gravity Brans–Dicke theory Solutions Schwarzschild Reissner–Nordström Gödel Kerr Kerr–Newman Kasner Taub–NUT Milne Robertson–Walker pp-wave van Stockum dust Scientists Einstein Lorentz Hilbert Poincaré Schwarzschild de Sitter Reissner Nordström Weyl Eddington Friedmann Milne Zwicky Lemaître Gödel Wheeler Robertson Bardeen Walker Kerr Chandrasekhar Ehlers Penrose Hawking Taylor Hulse Stockum Taub Newman Yau Thorne Weiss Bondi Misner others