New Massive Binaries in the Cygnus OB2 Association

TL;DR

This study reports new orbital solutions for six massive binary systems in Cygnus OB2, expanding the known population and providing insights into their orbital characteristics and distribution.

Contribution

It presents the first orbital solutions for several massive binaries in Cygnus OB2, including eclipsing and spectroscopic systems, enhancing understanding of their orbital parameters.

Findings

Six new massive binary systems characterized

Orbital periods range from 1.5 to 19 days

No evidence for a twin-heavy binary distribution

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.