Radial velocity in a Wolf-Rayet/O-star couple

DOI

We present the first visual orbit for the nitrogen-rich Wolf-Rayet binary, WR133 (WN5o+O9I), based on observations made with the CHARA Array and the MIRC-X combiner. This orbit represents the first visual orbit for a WN star and only the third Wolf-Rayet star with a visual orbit. The orbit has a period of 112.8days, a moderate eccentricity of 0.36, and a separation of a=0.79 mas on the sky. We combine the visual orbit with an SB2 orbit and Gaia parallax to find that the derived masses of the component stars are M_WR_=9.3{+/-}1.6M{odot} and M_O_=22.6{+/-}3.2M{odot}, with the large errors owing to the nearly face-on geometry of the system combined with errors in the spectroscopic parameters. We also derive an orbital parallax that is identical to the Gaia-determined distance. We present a preliminary spectral analysis and atmosphere models of the component stars, and find the mass-loss rate in agreement with polarization variability and our orbit. However, the derived masses are low compared to the spectral types and spectral model. Given the close binary nature, we suspect that WR133 should have formed through binary interactions, and represents an ideal target for testing evolutionary models given its membership in the cluster NGC6871.

Identifier
DOI http://doi.org/10.26093/cds/vizier.19089003
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/908/L3
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/908/L3
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/908/L3
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/908/L3
Provenance
Creator Richardson N.D.; Lee L.; Schaefer G.; Shenar T.; Sander A.A.C.; Hill G.M.,Fullard A.G.; Monnier J.D.; Anugu N.; Davies C.L.; Gardner T.,Lanthermann C.; Kraus S.; Setterholm B.R.
Publisher CDS
Publication Year 2024
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy