What is the name of the proposed maximum mass limit for a stable neutron star?
Answer
Tolman–Oppenheimer–Volkoff limit
The Tolman–Oppenheimer–Volkoff limit is the proposed maximum mass of a stable, nonrotating neutron star. Above it, no known pressure mechanism can prevent further gravitational collapse, potentially producing a black hole.
The limit is not a single precisely measured number because it depends on the poorly known equation of state of ultra-dense nuclear matter. Modern estimates commonly place it around 2 to 3 solar masses, though the exact value remains an active research question.
Richard Tolman, J. Robert Oppenheimer, and George Volkoff developed the relativistic framework in the 1930s. The limit differs from the Chandrasekhar limit, which concerns white dwarfs supported by electron degeneracy pressure. Rotation can temporarily allow a neutron star to support more mass than the nonrotating limit.