Visual Orbit and Individual Masses of the Single-lined Spectroscopic Binary 94 AQR A (HD 219834A; MCA 74)

Abstract

By combining our improved visual orbit with the last spectroscopic solution of the single-lined spectroscopic binary, MCA 74 (ADS 16672Aa, Ab; HD 219834A), we derived its orbital solution to have a period of 6.321 years. Using the Gaia parallax, a systemic mass of 1.87 ± 0.09 {{ \mathcal M }}_⊙ and a mass ratio of q = 0.725 were obtained, which yielded individual masses of 1.07 ± 0.06 {{ \mathcal M }}_⊙ and 0.80 ± 0.04 {{ \mathcal M }}_⊙ for the main and the secondary components, respectively. The mass and the absolute magnitude of +3.52 confirm that the primary is a late G5-G8 subgiant, while the same parameters of the secondary (Mv = +6.52) suggest that it is an early K2-K3 dwarf.