posydon.binary_evol.DT.gravitational_radiation

posydon.binary_evol.DT.gravitational_radiation.default_gravrad

posydon.binary_evol.DT.gravitational_radiation.default_gravrad.default_gravrad(a, e, primary, secondary, verbose=False)[source]

Calculates the change in orbital separation and eccentricity

due to gravitational wave radiation, according to:

Junker, W., & Schafer, G. 1992, MNRAS, 254, 146

Parameters:

  • a (float) – The current orbital separation. [Rsolar]

  • e (float) – The current orbital eccentricity.

  • primary (SingleStar object) – A single star object, representing the primary (more evolved) star in the binary and containing its properties.

  • secondary (SingleStar object) – A single star object, representing the secondary (less evolved) star in the binary and containing its properties.

  • verbose (bool) – True if we want to print stuff.

Returns:

  • da (float) – The change in orbital separation for a time step in

  • step_detached’s solve_ivp(). [Rsolar/yr]

  • de (float) – The change in orbital eccentricity for a time step in

  • step_detached’s solve_ivp().