We report the discovery and orbital solutions for two new OB binaries in the Cygnus OB2 Association, MT311 (B2V+B3V) and MT605 (B0.5V+B2.5:V). We also identify the system MT429 as a probable triple system consisting of a tight eclipsing 2.97 day B3V+B6V pair and a B0V at a projected separation of 138 AU. We further provide the first spectroscopic orbital solutions to the eclipsing, double-lined, O-star binary MT696 (O9.5V+B1:V), the double-lined, early B binary MT720 (B0-1V+B1-2V), and the double-lined, O-star binary MT771 (O7V+O9V). These systems exhibit orbital periods between 1.5 days and 12.3 days, with the majority having P<6 days. The two new binary discoveries and six spectroscopic solutions bring the total number of known massive binaries in the central region of the Cygnus OB2 Association to 20, with all but two having full orbital solutions.
@article{arxiv.1112.3383,
title = {Additional Massive Binaries in the Cygnus OB2 Association},
author = {Daniel C. Kiminki and Henry A. Kobulnicky and Ian Ewing and Megan M. Bagley Kiminki and Michael Lundquist and Michael Alexander and Carlos Vargas-Alvarez and Heather Choi and Calen B. Henderson},
journal= {arXiv preprint arXiv:1112.3383},
year = {2015}
}
Comments
42 pages, 16 figures, accepted for publication in the Astrophysical Journal, minor typos have been fixed