2005MNRAS.359..688N

We present the analysis of an extensive set of high-resolution spectroscopic observations of HD 93161, a visual binary with a separation of 2 arcsec. HD 93161 A is a spectroscopic binary, with both components clearly detected throughout the orbit. The primary star is most probably of spectral type O8V, while the secondary is likely an O9V. We obtain the first orbital solution for this system, characterized by a period of 8.566±0.004 d. The minimum masses of the primary and secondary stars are 22.2±0.6 and 17.0±0.4 M_☉, respectively. These values are quite large, suggesting a high inclination of the orbit. The second object, HD 93161 B, displays an O6.5V(f) spectral type and is thus slightly hotter than its neighbour. This star is at first sight single but presents radial velocity variations. Finally, we study HD 93161 in the X-ray domain. No significant variability is detected. The X-ray spectrum is well described by a 2T model with kT₁∼ 0.3 keV and kT₂∼ 0.7 keV. The X-ray luminosity is rather moderate, without any large emission excess imputable to a wind interaction.