We present the analysis of an extensive set of high-resolution spectroscopic observations of HD 93161 , a visual binary with a separation of 2″ .
HD 93161A 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 \pm 0.004 days .
The minimum masses of the primary and secondary stars are 22.2 \pm 0.6 M _ { \odot } and 17.0 \pm 0.4 M _ { \odot } respectively .
These values are quite large , suggesting a high inclination of the orbit .
The second object , HD 93161B , 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 . We finally 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 k T _ { 1 } \sim 0.3 keV and k T _ { 2 } \sim 0.7 keV .
The X-ray luminosity is rather moderate , without any large emission excess imputable to a wind interaction .