The orbit and stellar masses of the archetype colliding-wind binary WR 140
Item Type Article; text
Authors Thomas, J.D.; Richardson, N.D.; Eldridge, J.J.; Schaefer, G.H.; Monnier, J.D.; Sana, H.; Moffat, A.F.J.; Williams, P.; Corcoran, M.F.; Stevens, I.R.; Weigelt, G.; Zainol, F.D.; Anugu, N.; Le Bouquin, J.-B.; Ten Brummelaar, T.; Campos, F.; Couperus, A.; Davies, C.L.; Ennis, J.; Eversberg, T.; Garde, O.; Gardner, T.; Fló, J.G.; Kraus, S.; Labdon, A.; Lanthermann, C.; Leadbeater, R.; Lester, T.; Maki, C.; McBride, B.; Ozuyar, D.; Ribeiro, J.; Setterholm, B.; Stober, B.; Wood, M.; Zurmühl, U.
Citation Thomas, J. D., Richardson, N. D., Eldridge, J. J., Schaefer, G. H., Monnier, J. D., Sana, H., Moffat, A. F. J., Williams, P., Corcoran, M. F., Stevens, I. R., Weigelt, G., Zainol, F. D., Anugu, N., Le Bouquin, J.-B., Ten Brummelaar, T., Campos, F., Couperus, A., Davies, C. L., Ennis, J., … Zurmühl, U. (2021). The orbit and stellar masses of the archetype colliding-wind binary WR 140. Monthly Notices of the Royal Astronomical Society, 504(4), 5221–5230.
DOI 10.1093/mnras/stab1181
Publisher Oxford University Press
Journal Monthly Notices of the Royal Astronomical Society
Rights Copyright © 2021 The Author(s).
Download date 25/09/2021 08:43:37
Item License http://rightsstatements.org/vocab/InC/1.0/
Version Final published version Link to Item http://hdl.handle.net/10150/660807 MNRAS 504, 5221–5230 (2021) doi:10.1093/mnras/stab1181 Advance Access publication 2021 April 30
The orbit and stellar masses of the archetype colliding-wind binary WR 140
Joshua D. Thomas ,1‹ Noel D. Richardson ,2‹ J. J. Eldridge ,3 Gail H. Schaefer,4 John D. Monnier,5 Hugues Sana ,6 Anthony F. J. Moffat,7 Peredur Williams ,8 Michael F. Corcoran,9,10 Ian R. Stevens ,11 Gerd Weigelt,12 Farrah D. Zainol,11 Narsireddy Anugu,13,14 Jean-Baptiste Le Bouquin,15 Theo ten Brummelaar,4 Fran Campos,16 Andrew Couperus,1,17 Claire L. Davies ,13 Jacob Ennis,5 Downloaded from https://academic.oup.com/mnras/article/504/4/5221/6261199 by University of Arizona user on 19 July 2021 Thomas Eversberg,18 Oliver Garde,19 Tyler Gardner,5 Joan Guarro Flo,´ 20 Stefan Kraus,13 Aaron Labdon,13 Cyprien Lanthermann,6,15 Robin Leadbeater,21 T. Lester,22 Courtney Maki,1 Brendan McBride,1 Dogus Ozuyar ,23 J. Ribeiro,24 Benjamin Setterholm,5 Berthold Stober,25 Mackenna Wood1 and Uwe Zurmuhl¨ 26 Affiliations are listed at the end of the paper
Accepted 2021 April 21. Received 2021 April 21; in original form 2020 March 6
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 MWR = 10.31 ± 0.45 M and MO = 29.27 ± 1.14 M . 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. Key words: binaries: general – stars: fundamental parameters – stars: Wolf–Rayet – stars: winds; outflows – stars: individual: WR 140.
WR 140 is a very intriguing object; with a long period 1 INTRODUCTION (P = 7.992 yr) and a high eccentricity (e = 0.8993), the system Mass is the most fundamental property of a star, as it constrains most has some resemblance to the enigmatic massive binary η Carinae. properties of its evolution. Accurate stellar mass determinations are It has a double-lined spectroscopic and visual orbit, meaning that therefore critical to test stellar evolutionary models and to measure we possess exceptional constraints on the system’s geometry at any the effects of binary interactions. So far, only two carbon-rich epoch. Wolf–Rayet (WR) stars have established visual and double-lined WR 140 was one of the first WC stars found to exhibit infrared spectroscopic orbits, the hallmark of mass measurements. They are variability attributed to dust formation (Williams et al. 1978). Its γ 2 Velorum (WC8 + O7.5III-V; North et al. 2007;Lambertsetal. radio, and X-ray emissions, along with the dusty outbursts in the 2017; Richardson et al. 2017) and WR 140 (Fahed et al. 2011; infrared, were originally proposed to be modulated by its binary orbit Monnier et al. 2011). by Williams et al. (1990). Williams et al. (2009) showed that dust γ 2 Vel contains the closest WR star to us at 336 pc (Lamberts production was indeed modulated by the elliptical orbit. Recently, et al. 2017), allowing interferometry to resolve the close 78-d orbit. Lau et al. (2020) showed that WC binaries with longer orbital The only other WR system with a reported visual orbit is WR 140 periods produced larger dust grains than shorter period systems. (Monnier et al. 2011), a long-period highly eccentric system and a Therefore, the accurate determination of all related properties of benchmark for massive colliding-wind systems, and the subject of these binaries can help test this trend, and provide critical constraints this paper. The only nitrogen-rich WR binary with a resolved orbit on mechanisms that produce dust in these systems. is WR 133, which was recently reported by Richardson et al. (2021). The orbital properties and apparent brightness of WR 140 make Some progress has also been made in increasing this sample by it an important system for the study of binary evolution. As one of Richardson et al. (2016), who resolved the long-period systems the few WR stars with an exceptionally well-determined orbit, it WR 137 and WR 138 with the CHARA Array. serves as an important astrophysical laboratory for dust production (e.g. Williams et al. 2009) and colliding-wind shock physics (e.g. Sugawara et al. 2015). In this paper, we present refined orbital param- E-mail: [email protected] (JDT); [email protected] (NDR) eters based on new interferometric and spectroscopic measurements