Light minimum times of TY Boo

For the assumed third body, the period and eccentricity of the light-time orbit are P_3_=58.6yr and e'=0.1744, respectively. If the existence of an additional unseen body is true, this binary may be a tertiary system. The long-term orbital period decrease suggests that TY Boo is undergoing a mass transfer from the primary component to the secondary component at a rate of dm/dt=-3.15x10^-8^M_{sun}_/yr for equation (2) or dm/dt=-2.90x10^-8^M_{sun}_/yr for equation (3).

As its mass transfers, accompanied by angular momentum loss due to mass outflow L_2_, this binary will evolve into a deep contact configuration.