APPARENT ORBIT OF THE SPECTROSCOPIC BINARY BETA-ARIETIS WITH THE MARK-III STELLAR INTERFEROMETER

The spectroscopic binary β Ari has been directly resolved with the Mark III Stellar Interferometer. Observations in 1988 were analyzed to determine the visual orbit of the system with the following results: eccentricity e = 0.903 ± 0.012, semimajor axis a" = 0".0361 ± 0".0003, inclination i = 44°.7 ± 1°.3, longitude of periastron w = 209°.1 ± 1°.2, position angle of ascending node Ω= 79°.1 ± 0°.8. The measured magnitude difference between two components, Δm = 2.63 ± 0.22 at 800 nm, yields individual visual magnitudes of mv1 = 2.70 ± 0.02 and mv2 = 5.80 ± 0.20. Combined with data from spectroscopic observations, masses M1 = (2.34 ± 0.10) M⊙, M2 = (1.34 ± 0.07) M⊙, and geometrical parallax π= 0".053 ± 0".002 are derived. These results demonstrate that both components of β Ari agree well with the empirical mass-luminosity relation.