BSE evolution model

The high-level binary evolution model is shown in Figure 4.

Figure 4 High-level BSE evolution.

The binary evolution model is driven by the Evolve() function in the BaseBinaryStar class, which evolves the star through its entire lifetime by doing the following:

if touching
    STOP = true
else
    calculate initial time step
    STOP = false

DO WHILE NOT STOP AND NOT max iterations:

    evolve a single time step
        evolve each constituent star a single time step (see the :ref:`SSE evolution model`)

    if error OR unbound OR touching OR Massless Remnant
        STOP = true
    else
        evaluate the binary
            calculate mass transfer
            calculate winds mass loss

            if common envelope
                resolve common envelope
            else if supernova
                resolve supernova
            else
                resolve mass changes

            evaluate supernovae
            calculate total energy and angular momentum
            update magnetic field and spin: both constituent stars

        if unbound OR touching OR merger
            STOP = true
        else
            if NS+BH
                resolve coalescence
                STOP = true
            else
                if WD+WD OR max time
                    STOP = true
                else
                    if NOT max iterations
                        calculate new time step