Rotational modulation and high speed streams in FK Comae Berenices: Evidence for a massive, highly-evolved binary system

Abstract

The authors obtained high resolution spectroscopic observations of FK Com in the spring of 1983 using the IUE and the 2.1 m coudé at KPNO. The emission lines are broad, and unlike any active late-type stars known to the authors. FK Com is modeled as a high mass ratio, mass transferring binary, wherein the mass ratio has reversed due to Roche lobe overflow. It consists of stars with 4 M_sun; and 0.2 M_sun; and with radii of 6 R_sun; and 2.8 R_sun;. The semi-major axis is 12.5 R_sun;.