Hayashi limit

plural Hayashi limits

1. astrophysicsA theoretical maximum radius of a star of given mass; the radius at which the inward force of gravity exactly balances the outward pressure of the gas of the star.

   When a star is fully within hydrostatic equilibrium—a condition where the inward force of gravity is matched by the outward pressure of the gas—the star can not exceed the radius defined by the Hayashi limit.^([Wikipedia])

   3 more examples

   However, the approximate locations of the Hayashi limits point to remarkably low masses for the three T Tauri stars investigated here. It should be noted, that the Hayashi limits are valid only for stars in hydrostatic equilibrium.

   1977, Rudolf Kippenhahn, Walter Strohmeyer, The Interaction of Variable Stars with Their Environment, Remeis-Sternwarte, page 69

   Since the Hayashi limit approaches close to the main sequence at about 1 M⊙, the 'Hertzsprung gap' between the terminal main sequence and the Hayashi limit is much less marked than at high masses.

   2006, Peter Eggleton, Evolutionary Processes in Binary and Multiple Stars, Cambridge University Press, page 75

   The latest-type RSGs^([Red Supergiants]) in the Magellanic Clouds are cooler than the current evolutionary tracks allow, occupying the region to the right of the Hayashi limit where stars are no longer in hydrostatic equilibrium.

   2009, Donald Gerard Luttermoser, Beverly Joy Smith, Robert E. Stencel, editors, The Biggest, Baddest, Coolest Stars: Proceedings of a Workshop, Astronomical Society of the Pacific, page 33