The maximum mass of a star's helium core that can support the outer parts of the star against gravitational collapse, once the hydrogen at its centre has been exhausted. The limit is about 10–15% of the total mass of the star. If the mass of helium in the core exceeds this limit, the central parts collapse while the outer part expands rapidly to become a red giant. Calculations suggest that this happens only in massive stars. The limit is named after S. Chandrasekhar and the Brazilian astrophysicist Mario Schönberg (1914–90).
Subjects: Astronomy and Astrophysics.