Refining Orbits of Bright Binary Systems

Abstract

We obtained spectra of several bright binary systems (ζ02 UMa, 2 Lac, and ϕ Aql), which were mostly observed with photographic plates and whose orbits were not determined very accurately. Each system was monitored for a few years with the 81-cm telescope equipped with an échelle spectrograph at the Three College Observatory in North Carolina. The spectra were taken in a wavelength range between 4000 and 7900 Å with a spectral resolution of R∼ 12,000. Radial velocity measurements were done using cross-correlation in selected spectral regions or by measuring positions of individual spectral lines. Refined orbits and stellar parameters are presented.