A broad gravitational-wave catalog has now pinned down a black-hole mass gap above about 45 solar masses, matching long-standing predictions from pair-instability supernova physics.
Signals above that threshold show a high-spin population, pointing to black holes built through repeated mergers in dense star clusters rather than direct stellar collapse.
The inferred edge of the gap also narrows estimates for the carbon-to-oxygen fusion rate during helium burning in massive stars, linking merger data to stellar nuclear physics.
The result turns gravitational-wave observations into a probe of both how the heaviest stellar black holes form and how massive stars evolve before they explode.
How do colliding black holes reveal the nuclear secrets of long-dead massive stars?
Are giant black holes born from cosmic collisions or are they ancient relics from the Big Bang?
Can we now probe the fiery hearts of stars using only the faint ripples of spacetime?
Mapping the Black Hole Mass Gap: New Observational Proof and the Physics Behind the Void
Overview
Recent discoveries in May and June 2026, using advanced gravitational wave detections, have definitively confirmed the existence of a mass gap in the black hole mass spectrum. This breakthrough is supported by compelling observational evidence, including the identification of an effective-spin transition at high black hole masses and a distinct transition point in the mass distribution. These findings map out the boundaries of the black hole mass spectrum and solidify the long-hypothesized void, marking a major step forward in understanding how black holes form and evolve.