Orbits of Small Angular Scale Binaries Resolved with the Mark III Interferometer

Abstract

We present relative orbits of eight spectroscopic binaries with semimajor axes ranging from 3 milliarcsec (mas) to 10 mas. The stars, π Andromedae, θ Aquilae, β Aurigae, ζ<SUP>1</SUP> Ursae Majoris, 93 Leonis, 113 Herculis, β Trianguli, and δ Trianguli, represent some of the smallest angular scale binaries resolved with the Mark III optical interferometer on Mount Wilson, California. In addition to the orbital elements, we measured the magnitude difference between the components at λλ8OO, 550, 500, and 450 nm. Spectroscopic orbital elements for both primary and secondary components are available for all stars except 113 Herculis. The available data allow the determination of the distance to four of the binaries, as well as of their component masses and luminosities. The results are compared with stellar evolution models.