Long-term coupled stellar–tidal evolution of two solar-mass stars for various assumptions. Red curves represent stars that experience the CPL tidal model and constant radius of gyration r_g ; purple curves are the CPL with evolving r_g; orange curves are the CTL tidal model with constant r_g; and pale blue curves are the CTL with evolving r_g. Top: evolution of the stability limit a_crit. Middle: orbital period of the binary star. Bottom: binary’s orbital eccentricity. The approximate runtime was 40 min in total. github.com: cbp_dynamic_stability/STEEP/