New Massive Binaries in the Cygnus OB2 Association

Abstract

As part of an ongoing study to determine the distribution of orbital parameters for massive binaries in the Cygnus OB2 Association, we present the orbital solutions for two new single-lined spectroscopic binaries, MT059 (O8V) & MT258 (O8V), and one double-lined eclipsing binary (Schulte 3). We also constrain the orbital elements of three additional double-lined systems (MT252, MT720, MT771). Periods for all systems range from 1.5-19 days and eccentricities range from 0-0.11. The six new OB binary systems bring the total number of multiple systems within the core region of Cyg OB2 to 11. The current sample does not show evidence for a ``twin-heavy'' binary distribution.