The Spectroscopic Orbit of 6-DRACONIS

Abstract

6 Dra has long been known to show small variations in radial velocity, and there is photometric and spectroscopic evidence that its spectrum is composite. We show, largely on the basis of a generous number of photoelectric radial velocities mainly obtained at Cambridge and Fick observatories, that the orbit is of mild eccentricity and has a period of 562 days and a semi-amplitude of 7 km s‑1.IUE observations show that the spectrum between 1600 and 1800 ∢ is consistent with its arising from a late-A main-sequence companion