What theoretical limit governs the maximum stable mass for a neutron star like a magnetar?
The Tolman-Oppenheimer-Volkoff (TOV) limit
The absolute maximum mass that a neutron star can support against the overwhelming force of its own gravity before succumbing to complete collapse is defined by a critical threshold known in astrophysics as the Tolman-Oppenheimer-Volkoff (TOV) limit. When a stellar remnant, regardless of whether it is a standard neutron star or a magnetar, exceeds this threshold—a point where even the outward pressure generated by degenerate neutrons fails to resist gravity—an unstoppable implosion begins. This boundary condition is fundamental to determining the ultimate fate of these ultra-dense objects, signaling the irreversible transition toward forming a singularity.

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