The orbit and stellar masses of the archetype colliding-wind binary WR 140
Joshua D. Thomas, Noel D. Richardson, J. J. Eldridge, Gail Schaefer, John D. Monnier, H. Sana, A. F. J. Moffat, P. M. Williams, M. F. Corcoran, I. R. Stevens, G. Weigelt, Farrah D Zainol, Narsireddy Anugu, J.-B. Le Bouquin, Theo ten Brummelaar, F. Campos, Andrew A. Couperus, Claire L. Davies, Jacob Ennis, Thomas Eversberg, O. Garde, Tyler Gardner, Joan Guarro Fló, Stefan Kraus, Aaron Labdon, Cyprien Lanthermann, R. Leadbeater, T. Lester, Courtney Maki, Brendan McBride, D. Özuyar, J. Ribeiro, Benjamin R. Setterholm, Berthold Stober, Mackenna L. Wood, Uwe Zurmühl
Abstract
ABSTRACT We present updated orbital elements for the Wolf–Rayet (WR) binary WR 140 (HD 193793; WC7pd + O5.5fc). The new orbital elements were derived using previously published measurements along with 160 new radial velocity measurements across the 2016 periastron passage of WR 140. Additionally, four new measurements of the orbital astrometry were collected with the CHARA Array. With these measurements, we derive stellar masses of $M_{\rm WR} = 10.31\pm 0.45 \, \mathrm{M}_\odot$ and $M_{\rm O} = 29.27\pm 1.14 \, \mathrm{M}_{\odot }$. We also include a discussion of the evolutionary history of this system from the Binary Population and Spectral Synthesis model grid to show that this WR star likely formed primarily through mass-loss in the stellar winds, with only a moderate amount of mass lost or transferred through binary interactions.